| 1. |
- Fiedler, Heidelore, 1953-, et al.
(författare)
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The need for capacity building and first results for the Stockholm convention global monitoring plan
- 2013
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Ingår i: TrAC. Trends in analytical chemistry. - : Elsevier BV. - 0165-9936 .- 1879-3142. ; 46, s. 72-84
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Tidskriftsartikel (refereegranskat)abstract
- The Stockholm Convention on Persistent Organic Pollutants (POPs) established an effectiveness evaluation to assess the efficiency of measures taken by Parties under the Convention. Among these measures, a Global Monitoring Plan requires countries to analyze core matrices for POPs. To assist countries in setting up networks for these core matrices and to generate high-quality, comparable results, the United Nations Environment Program has implemented projects in 32 developing countries. The results demonstrate the worldwide presence of POPs in air and in humans, although at different scales.
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| 2. |
- Goebl, D., et al.
(författare)
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Auger neutralization of He+ on Cu surfaces : Simulation of azimuthal scans
- 2013
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 317:Part A, s. 23-27
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Tidskriftsartikel (refereegranskat)abstract
- Charge exchange by Auger neutralization (AN) plays an important role in surface analysis techniques such as low energy ion scattering (LEIS). Recent advances in the theoretical description of AN have included a model based on a linear combination of atomic orbitals (LCAO) approach, which is able to calculate accurate neutralization probabilities of He+ due to AN in LEIS. Previous investigations have shown that the neutralization probability is strongly influenced by the distance dependent shift of the He 1s level. In this study simulations of He+ scattered from Cu(100) and Cu(110) surfaces at fixed azimuth angles are presented. Additionally, the azimuth dependence of ion- and neutral-yield for He+ scattered from Cu(100) is simulated and compared to experimental data. Calculations were performed using the LCAO model in combination with molecular dynamics simulations. The excellent agreement between simulation and experiment provides evidence that the obtained values for the level shift are a characteristic property of the surface.
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| 3. |
- Goebl, D., et al.
(författare)
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Quasi-resonant neutralization of He+ ions at a germanium surface
- 2013
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 25:48, s. 485006-
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Tidskriftsartikel (refereegranskat)abstract
- When low-energy He ions are scattered from a Ge surface, the fraction of positive ions exhibits characteristic oscillations as a function of ion energy. These oscillations are caused by quasi-resonant neutralization (qRN), a process which is active for materials with a narrow band nearly resonant with the unperturbed He 1s-level. In this paper we measure the fraction of He+ backscattered from Ge(100). In conjunction with recently developed theoretical methods, we extract quantitative information on the efficiency of qRN. Our evaluation reveals that qRN is a highly efficient process leading to ion fractions two orders of magnitude lower than in systems for which neutralization is only due to Auger processes.
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| 4. |
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| 5. |
- Smith, P., et al.
(författare)
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How much land-based greenhouse gas mitigation can be achieved without compromising food security and environmental goals?
- 2013
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Ingår i: Global Change Biology. - : Wiley. - 1365-2486 .- 1354-1013. ; 19:8, s. 2285-2302
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Forskningsöversikt (refereegranskat)abstract
- Feeding 9-10billion people by 2050 and preventing dangerous climate change are two of the greatest challenges facing humanity. Both challenges must be met while reducing the impact of land management on ecosystem services that deliver vital goods and services, and support human health and well-being. Few studies to date have considered the interactions between these challenges. In this study we briefly outline the challenges, review the supply- and demand-side climate mitigation potential available in the Agriculture, Forestry and Other Land Use AFOLU sector and options for delivering food security. We briefly outline some of the synergies and trade-offs afforded by mitigation practices, before presenting an assessment of the mitigation potential possible in the AFOLU sector under possible future scenarios in which demand-side measures codeliver to aid food security. We conclude that while supply-side mitigation measures, such as changes in land management, might either enhance or negatively impact food security, demand-side mitigation measures, such as reduced waste or demand for livestock products, should benefit both food security and greenhouse gas (GHG) mitigation. Demand-side measures offer a greater potential (1.5-15.6Gt CO2-eq. yr(-1)) in meeting both challenges than do supply-side measures (1.5-4.3Gt CO2-eq. yr(-1) at carbon prices between 20 and 100US$ tCO(2)-eq. yr(-1)), but given the enormity of challenges, all options need to be considered. Supply-side measures should be implemented immediately, focussing on those that allow the production of more agricultural product per unit of input. For demand-side measures, given the difficulties in their implementation and lag in their effectiveness, policy should be introduced quickly, and should aim to codeliver to other policy agenda, such as improving environmental quality or improving dietary health. These problems facing humanity in the 21st Century are extremely challenging, and policy that addresses multiple objectives is required now more than ever.
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