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961.
T.M. McIntire O.S. Ryder P.L. Gassman Z. Zhu S. Ghosal B.J. Finlayson-Pitts 《Atmospheric environment (Oxford, England : 1994)》2010,44(7):939-944
It is commonly assumed that atmospheric oxidation of hydrocarbon particles or hydrocarbon coatings on particles leads to polar products and increased water uptake, altering atmospheric visibility and increasing the likelihood they will act as cloud condensation nuclei (CCN). We show here through laboratory experiments that increased water uptake depends on the 3-dimensional structure of the particles. Laboratory studies of particles formed during ozonolysis of surface-bound alkenes, present as terminally unsaturated self-assembled monolayers (C8= SAM) on a silica substrate, were carried out at room temperature and 1 atm pressure. SAMs were exposed to ~1013 O3 molecules cm?3 for 40 min and resultant particles were analyzed using single particle Fourier transform infrared micro-spectroscopy (micro-FTIR) and secondary ion mass spectroscopy (SIMS). Spectroscopy results show that –COOH and other polar groups are formed but are buried inside a hydrophobic shell, consistent with earlier observations (McIntire et al., 2005, Moussa et al., 2009) that water uptake does not increase after reaction of the terminal alkene with O3. These insights into the 3-D structure of particles formed on oxidation have important implications for the ability of secondary organic aerosols to act as CCN. In addition, the nature of the surface of the particles is expected to determine their uptake into biological systems such as the surface of the lungs. 相似文献
962.
M. Tainio J.T. Tuomisto J. Pekkanen N. Karvosenoja K. Kupiainen P. Porvari M. Sofiev A. Karppinen L. Kangas J. Kukkonen 《Atmospheric environment (Oxford, England : 1994)》2010,44(17):2125-2132
The emission-exposure and exposure-response (toxicity) relationships are different for different emission source categories of anthropogenic primary fine particulate matter (PM2.5). These variations have a potentially crucial importance in the integrated assessment, when determining cost-effective abatement strategies. We studied the importance of these variations by conducting a sensitivity analysis for an integrated assessment model. The model was developed to estimate the adverse health effects to the Finnish population attributable to primary PM2.5 emissions from the whole of Europe. The primary PM2.5 emissions in the whole of Europe and in more detail in Finland were evaluated using the inventory of the European Monitoring and Evaluation Programme (EMEP) and the Finnish Regional Emission Scenario model (FRES), respectively. The emission-exposure relationships for different primary PM2.5 emission source categories in Finland have been previously evaluated and these values incorporated as intake fractions into the integrated assessment model. The primary PM2.5 exposure-response functions and toxicity differences for the pollution originating from different source categories were estimated in an expert elicitation study performed by six European experts on air pollution health effects. The primary PM2.5 emissions from Finnish and other European sources were estimated for the population of Finland in 2000 to be responsible for 209 (mean, 95% confidence interval 6–739) and 357 (mean, 95% CI 8–1482) premature deaths, respectively. The inclusion of emission-exposure and toxicity variation into the model increased the predicted relative importance of traffic related primary PM2.5 emissions and correspondingly, decreased the predicted relative importance of other emission source categories. We conclude that the variations of emission-exposure relationship and toxicity between various source categories had significant impacts for the assessment on premature deaths caused by primary PM2.5. 相似文献
963.
A.M.M. Manders M. Schaap X. Querol M.F.M.A. Albert J. Vercauteren T.A.J. Kuhlbusch R. Hoogerbrugge 《Atmospheric environment (Oxford, England : 1994)》2010,44(20):2434-2442
The oceans are a major source for particles that play an important role in many atmospheric processes. In Europe sea salt may contribute significantly to particulate matter concentrations. We have compiled sodium concentration data as a tracer for sea salt for 89 sites in Europe to provide more insight in the distribution of sea salt across Europe. The annual average sea salt concentrations above land were estimated to range between 0.3 and almost 13 μg m?3. Maximum concentrations are found at the Irish coast. At coastal sites along the Atlantic and North Sea coast concentrations tend to be around 5 μg m?3. More inland locations up to about 300 km away from the coast tend to show concentrations between 2 and 5 μg m?3, whereas sites further away from the coast are characterized by lower concentrations. An analysis of the representativity of the data with respect to a long term average showed that the long average is associated with a standard deviation of around 15%. The compilation of observations provides an improved overview of sea salt concentrations in Europe as well as an improved basis for model validation. Verification of the results of the LOTOS-EUROS model learned that the model represents well the spatial variability of the observed sea salt concentrations very well. However, the absolute concentrations are significantly overestimated due to large uncertainties in the emission and dry deposition parameterizations. Using the high explained variability in the gradients across Europe, the bias-corrected modelled distribution serves as a best estimate of the sea salt distribution across Europe for 2005. 相似文献
964.
965.
According to various reports, climate change is responsible for the change in rainfall amount and pattern accompanied by the
various degrees of extreme events in Sahelian West Africa in recent years. Other reports also suggest that there has been
a “recovery” of the rainy season (Nicholson 2005). In this study, temporal characteristics of meteorological droughts in the Volta basin, a semi-arid region in West Africa,
are investigated in order to provide a guide for sustainable water resource management. For this purpose, drought intensity,
areal extent and recurrence frequency is analysed using the standardised precipitation index (SPI) for a time series between
1961 and 2005 from 52 meteorology stations across the Volta basin. Using this analysis the severity of the historical droughts
of 1961, 1970, 1983, 1992 and 2001 that occurred in the region are assessed and their intensity, areal extent and return periods
are obtained. The drought intensity is lower than −2.0 over nearly 75% of the region, meaning that a major part of the region
was under extreme drought conditions during this year. The drought of 1983/1984 has a probability of occurrence of up to 0.1
from records spanning 44 years. The areal extent of extreme drought conditions is about 90% during this drought period. 相似文献
966.
Towards institutional analysis of sustainability science: a quantitative examination of the patterns of research collaboration 总被引:2,自引:2,他引:0
This paper examines quantitatively the patterns of collaboration over geographical boundaries in the emerging field of sustainability
science by empirically analyzing the bibliometric data of scientific articles. The results indicate that an increasing number
of countries are engaged in research on sustainability, with the proportion of articles published through international collaboration
rising as well. The number of countries engaged in international collaboration on sustainability research has been increasing,
and the diversity of countries engaged in research collaboration beyond national borders is also increasing. The geographical
patterns of collaboration on sustainability show that research collaboration tends to be conducted between countries which
are geographically located closely, suggesting that communication and information exchange might be limited within the regional
clusters. The focused fields of research activities on sustainability are significantly different between countries, as each
country has its focused fields of research related to sustainability. The specialization of research activities is also observed
in international collaboration. While these patterns of international collaboration within regional clusters focusing on specific
fields could be effective in promoting the creation, transmission, and sharing of knowledge on sustainability utilizing the
already existing regional networks, they could pose a serious obstacle to collecting, exchanging, and integrating diverse
types of knowledge, especially when it is necessary to deal with problems involving large-scale complex interactions with
long-term implications, such as climate change. It would be of critical importance to establish inter-regional linkages by
devising appropriate institutional arrangements for global research collaboration on sustainability science. 相似文献
967.
Vo Thi Thanh Loc Simon R. Bush Le Xuan Sinh Nguyen Tri Khiem 《Environment, Development and Sustainability》2010,12(6):889-908
This paper investigates the structure, function and wealth distribution within the Pangasius hypophthalmus and Henicorhynchus spp./Labiobarbus spp. value chains in the Mekong Delta of Vietnam. The analysis is driven by key questions relating to the form and function
of value chains, their contribution to the livelihoods of farmers and fishers, the effectiveness of government policy and
the potential for value chain governance mechanisms, such as contracts and certification, to steer towards sustainable production.
The results indicate that actors in the high value Pangasius hypopthalmus export chain have a higher potential income, but face considerably higher economic vulnerability from global markets. Alternatively,
Henichorhychus/Labiobarbus spp. fishers are severely constrained in their ability to negotiate higher prices for their fish but appear to be less vulnerable
to economic and environmental change. The paper concludes that for value chain governance to improve the livelihoods of fishers
and farmers in both high and low value chains, new arrangements are needed that better accommodate customary institutions
and informal market relations. 相似文献
968.
Developed countries are major markets for developing country fresh produce. Demand by developed country consumers for spotless
produce has encouraged developing country consumers to rely increasingly on pesticides in producing fresh export vegetables.
However developed country pesticide standards enacted in response to reports of increased farmer and farm worker pesticide
poisoning and the food safety scandals of the 1980s and 1990s require changes in the way growers use pesticides. The EU has
especially developed stringent food safety standards relating to, among other things, pesticide usage. Under EU pesticide
standards (EU-PS) farmers are trained by their buyers on safe use of pesticides and then closely monitored under contract.
This paper looks at the impact of these standards on developing country farmers’ use of alternative pest management practices,
pesticide protective clothing and the actual usage of pesticides. It finds that compliance with EU-PS increases the use of
alternative pest management practices and protective clothing. However, EU-PS has mixed effect on the quantity of pesticides
used. The paper also finds that farmer’s education and access to information play an important role in the use of alternative
pest management practices. The paper concludes that EU-PS encourage the use of alternative pest management practices and pesticide
protective gear in production of fresh export vegetables. The findings imply that EU-PS promote environmentally-friendly methods
of production of fresh export vegetables in developing countries. 相似文献
969.
Courtney Fidler 《Environment, Development and Sustainability》2010,12(2):233-244
While the role Aboriginal people play in environmental governance programs are often underpinned by the Crown, Aboriginal
peoples are ratifying negotiated agreements with mining proponents to ensure their issues and concerns are addressed. This
paper examines Aboriginal participation in mine development to show how more inclusive social and environmental development
models can support a more sustainable development. Through two complementary processes, negotiated agreements and environmental
impact assessment, Aboriginal peoples are maximizing their benefits and minimizing the adverse impacts of a project to create
a more sustainable resource development. Case study analysis of the Galore Creek Project in northwestern British Columbia,
Canada, illustrates how environmental impact assessment and negotiated agreements can co-exist to positively contribute to
a successful mineral development, and hence operationalize sustainability within this context. 相似文献
970.
Mark Purdon 《Environment, Development and Sustainability》2010,12(6):1025-1050
Negotiations of the Kyoto Protocol reached what has been called a moral position on biocarbon sinks which saw important limitations
on their use in the Clean Development Mechanism (CDM), the Protocol’s main carbon offset system. After outlining this moral
position, this article examines the consequences of these limitations on the viability of community forest participation in
the CDM through a case study of three community forests in West Africa. Results suggest that there is significant carbon mitigation
potential from forest conservation, reforestation as well as from improved fuelwood cookstoves at the community level. Yet
under the current rules of the CDM, little of this overall carbon mitigation potential is able to be realized. Using qualitative
research methodologies, it was learned that community respondents showed a pragmatic, yet cautious interest in the CDM while
also emphasizing a need for land-use flexibility. The paper closes with a political discussion of the “‘moral position” on
biocarbon sinks in the carbon market and concludes with policy recommendations for biocarbon sinks, in both the CDM and REDD,
in the post-Kyoto climate change regime. 相似文献