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261.
Air pollution is one of the most pressing environmental problems which affects likewise urban, industrial and rural areas. Environmental planners, regulators and decision makers need reliable, scientifically based tools to find out strategies for controlling air pollution in a cost-effective way, taking into account the whole productive system. In this framework the basic elements of energy-environmental planning have to be extended to include also waste processing technologies amongst the usually considered pollution sources. Bottom-up optimizing models, based on linear programming techniques and customized for specific cases, represent a powerful tool in energy-environmental management. This paper focuses on the integrated modeling of material flows and energy system performed on a local scale case study (Basilicata Region, Southern Italy) using the linear programming model IEA-MARKAL. We have evaluated the feasibility of the model in representing the waste management system to estimate the environmental impact of the waste processing technologies in the context of the whole productive system. A sensitivity analysis has been carried out to emphasize the connections between tariffs, waste disposal technologies assessment and atmospheric emissions. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
262.
This article presents a case study of a successful effort to reach agreement on one of the most intractable environmental issues of our time: wolf management. This case is unusual in several ways. In this case, the members of the negotiating team were ordinary citizens rather than leaders of organized groups. This team was given an unusually high level of authority to write the plan as they saw fit; the agency pledged to implement “whatever they came up with.” The agency convened the process, but agency personnel were not members of the team and attended only when they were invited. The team members were able to reach agreement on this tough issue even though polar opposites were at the table—one who felt that wolves are a “spiritual essence” and another who felt that, as he put it, “wolves, coyotes, and cockroaches have a lot in common”. They produced a detailed plan that addressed all the issues in just 5 months. Another unusual aspect of this effort is that the final agreement does not list the team members. They explained that they wanted their plan to “stand alone” and be judged based on what it said, not on who was involved.However, just after their agreement was completed, a new, pro-wolf control government was elected that refused to endorse the plan. While the government gave various reasons for not ratifying the plan, more and more diverse interest groups came out in support for both the plan and the process that created it. Eventually, overwhelming public support forced the government to sign and implement the plan as written. This demonstrates that, while it is important for a team to seek the sanction of decision-makers, it is perhaps even more important for the general public to see the effort and the final agreement as fair. Strong support from a broad spectrum of the public can help win the necessary political support.In addition to discussing the unorthodox aspects of this consensus-building effort, this article also attempts to give the reader a front row seat to this process by using the informants' own words—words rich in detail, brimming with color and spoken straight from the heart. Certainly their experience dispels any notion that such efforts are simply a matter of following a recipe. During the process, members of the negotiating team experienced the entire gamut of emotions—anger, defeat, humor and, finally, a genuine sense of pride. As team member Patty Denison put it, “We showed that a random group of people could work together and do something truly monumental.”  相似文献   
263.
在一台六缸四冲程高压共轨柴油机上开展了乙醇/聚甲氧基二甲醚(PODE)/柴油混合燃料对内燃机燃烧和排放影响的试验研究.结果表明,在转速为1137 r·min-1,转矩为735 N·m的工况条件下,随着掺混PODE和乙醇比例的增大,双峰放热越来越明显,扩散燃烧速率增大,有效燃油消耗率增大,有效热效率降低,但降低幅度小于1%,其中,DPE5(PODE体积分数为20%,乙醇体积分数为5%)的有效热效率与D100(纯柴油)基本相当.提前主喷时刻、增大喷油压力均使有效热效率增大,CO和碳烟排放降低,NOx排放增大,而对降低HC排放的影响较小.相比D100,混合燃料可降低CO、HC、碳烟排放,在低喷油压力和较晚主喷时刻下,对碳烟的减排效果更为显著,最大降幅分别为85.5%(主喷时刻-1℃ A ATDC、喷油压力900 bar)和82.9%(主喷时刻-3℃ A ATDC、喷油压力600 bar),但不同混合燃料间的排放差异较小.综上所述,重型柴油机使用乙醇/PODE/柴油混合燃料可在热效率相当的前提下对排放有较大改善.  相似文献   
264.
Climate change adaptation strategies that aim to minimize harm and maximize benefits related to climate change impacts have mushroomed at all levels of government in recent years. While many studies have explored barriers that stand in the way of their implementation, the factors determining their potential to mainstream adaptation into various sectors are less clear. In the present paper, we aim to address this gap for two international, six national, and six local adaptation strategies. Based on document analyses and 35 semi‐structured interviews, the 14 case studies also explore in how far the factors facilitating climate change adaptation are similar across levels of government or level‐specific. Although located at three different levels of government, we find that the 14 adaptation strategies analyzed here represent “one‐size‐fits‐all governance arrangements” that are characterized by voluntariness and a lack institutionalization. Since adaptation strategies are relatively weak coordination hubs that are unable to force adaptation onto sectoral policy agendas, they rely mainly on sectoral self‐interest in adapting to climate change, largely determined by problem pressure. We conclude that one‐size‐fits‐all governance arrangements are rarely adequate responses to complex challenges, such as climate change. Although climate change adaptation depends more on framework conditions such as problem pressure than on administrative or governance features, the findings presented here can help to understand under what circumstances adaptation is likely to make progress.  相似文献   
265.
Generation of biodiesel from microalgae has been extensively investigated; however, its quality is often not suitable for use as fuel. Our investigation involved the evaluation of biodiesel quality using a native isolate Chlorella sorokiniana MIC-G5, as specified by American Society for Testing and Materials (ASTM), after transesterification of lipids with methanol, in the presence of sodium methoxide. Total quantity of lipids extracted from dry biomass, of approximately 410–450 mg g?1 was characterized using FTIR and 1H NMR. After transesterification, the total saturated and unsaturated fatty acid methyl esters (FAMEs) were 43% and 57%, respectively. The major FAMEs present in the biodiesel were methyl palmitate (C16:0), methyl oleate (C18:1), and methyl linoleate (C18:2), and the 1H NMR spectra matched with criteria prescribed for high-quality biodiesel. The biodiesel exhibited a density of 0.873 g cm–3, viscosity of 3.418 mm2 s?1, cetane number (CN) of 57.85, high heating value (HHV) of 40.25, iodine value of 71.823 g I2 100 g?1, degree of unsaturation (DU) of 58%, and a cold filter plugging point (CFPP) of –5.22°C. Critical fuel parameters, including oxidation stability, CN, HHV, iodine value, flash point, cloud point, pour point, density, and viscosity were in accordance with the methyl ester composition and structural configuration. Hence, C. sorokiniana can be a promising feedstock for biodiesel generation.  相似文献   
266.
The Passenger Pigeon (Ectopistes migratorius) was a social breeder, and it has been suggested that the species experienced functional extinction, defined as a total reproductive failure, prior to its actual extinction in the early years of the 20th century. We applied a novel randomization test based on the relative times of the most recent egg‐ and skin‐specimen sightings (i.e., recorded date of specimen collection) to test for functional extinction. For a total of 6 eggs and 27 skins, the observed significance level was 0.38, which indicated that the species did not become functionally extinct. Thus, proposals to reverse its rapid decline in the late 19th century could have been successful.  相似文献   
267.
Globalization and climate change threaten the sustained provision of essential ecosystem services (ES) for people living in and downstream of mountain regions. The increasing evidence of the many vulnerabilities of mountain social-ecological systems has highlighted the urgent need for policy-relevant research into ways of coping with these trends. In this context, resilience has been emerging as a concept for both understanding and managing the complex social-ecological systems in which ES are provided and consumed. Yet, literature on resilience of social-ecological systems is mainly theoretical with limited application in real-world mountain case studies. In this paper, we present a comprehensive quantitative assessment of the social-ecological resilience of a case study in the Swiss Alps under global change. We model and evaluate an indicator for resilience that shows the capacity of the mountain social-ecological system to provide a set of demanded ES. In a first step, we model the development of this indicator in different scenarios of global change. In a second step, we test the effect of a rich set of policy strategies under all these scenarios to identify types and timing of interventions that are robust under multiple global change settings. Results indicate that the resilience of the mountain social-ecological system is endangered in all scenarios, especially if strong globalization is assumed. Robust strategies that buffer the system against these pressures require early spatial planning action in combination with more targeted direct payments to support the current regional structure and traditional mountain farming practices. Such information is crucial to guide decision-making processes in the era of highly uncertain future global change.  相似文献   
268.
Animal movement patterns and use of space depend upon food and nonfood resources, as well as conspecific and heterospecific interactions, but models of habitat use often neglect to examine multiple factors and rarely include marsupials. We studied habitat use in an Australian population of koalas (Phascolarctos cinereus) over a 6-year period in order to determine how koalas navigate their environment and partition limited patchy food and nonfood resources. Tree selection among koalas appears to be mediated by folar chemistry, but nonfood tree selection exerts a major impact on home range use due to thermoregulatory constraints. Koalas moved on a daily basis, during both day and night, but daytime resting site was not necessarily in the same location as nighttime feeding site. Koalas had substantial home range overlap in the near absence of resource sharing with less than 1% of trees located in areas of overlap used by multiple koalas. We suggest that koala spatiotemporal distribution and habitat use are probably based upon a community structure of individuals, with a checkerboard model best describing overlap in home range area but not in resource use. Nonfood refugia and social networks should be incorporated into models of animal range and habitat use.  相似文献   
269.
Organochlorine compounds (PCBs, DDTs and HCB) in carcasses from a population of the Viperine Snake (Natrix maura) living in the Ebro Delta were analyzed. This is a wetland area on the Mediterranean coast where the natural ecosystem has been partially substituted by rice fields. High levels of pollutants (mainly DDTs and PCBs) have been detected in several species living in this area, due to the production of these compounds by a former industrial activity upstream as well as agricultural activity in the Delta. Organochlorines were analyzed in adult males and females, and in immature snakes. DDTs (mainly p,p′-DDE) were the most abundant pollutant present. The DDT/PCB ratio was higher than expected, which is consistent with the position of the Viperine Snake in the trophic web as well as the type of prey consumed. Immature snakes had more organochlorines than adults. However, the broad range of concentrations shown by immature snakes, suggested that part of the organochlorine load is transferred from gravid females to their eggs. In adults, organochlorine concentrations increased with carcass weight in both males and females. This increase was higher in males since females lost contaminants through fat investment during vitellogenesis. Seasonally, PCBs and DDTs levels increased in spring when snakes showed higher feeding activity, whereas higher levels of HCB were present at the end of summer, when the river input increased. Furthermore, HCB does not seem to biomagnify well across the trophic chain. Organochlorine concentrations in Viperine Snake carcasses were high since: 1) the dry tissue had less than 5% of fat, and 2) snakes were caught many years after the DDT ban, supporting the fact that cleaning of the ecosystem does not occur easily. These results indicate that snakes are adequate as indicators of the contamination in natural ecosystems but sex and body size of the samples should be taken into account for interpretation of results.  相似文献   
270.
Abstract: An essential foundation of any science is a standard lexicon. Any given conservation project can be described in terms of the biodiversity targets, direct threats, contributing factors at the project site, and the conservation actions that the project team is employing to change the situation. These common elements can be linked in a causal chain, which represents a theory of change about how the conservation actions are intended to bring about desired project outcomes. If project teams want to describe and share their work and learn from one another, they need a standard and precise lexicon to specifically describe each node along this chain. To date, there have been several independent efforts to develop standard classifications for the direct threats that affect biodiversity and the conservation actions required to counteract these threats. Recognizing that it is far more effective to have only one accepted global scheme, we merged these separate efforts into unified classifications of threats and actions, which we present here. Each classification is a hierarchical listing of terms and associated definitions. The classifications are comprehensive and exclusive at the upper levels of the hierarchy, expandable at the lower levels, and simple, consistent, and scalable at all levels. We tested these classifications by applying them post hoc to 1191 threatened bird species and 737 conservation projects. Almost all threats and actions could be assigned to the new classification systems, save for some cases lacking detailed information. Furthermore, the new classification systems provided an improved way of analyzing and comparing information across projects when compared with earlier systems. We believe that widespread adoption of these classifications will help practitioners more systematically identify threats and appropriate actions, managers to more efficiently set priorities and allocate resources, and most important, facilitate cross‐project learning and the development of a systematic science of conservation.  相似文献   
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