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- Paludan, C., et al.
(författare)
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Wetland management to reduce Baltic Sea eutrophication
- 2002
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Ingår i: Water Science and Technology. - London : IWA Publishing. - 0273-1223 .- 1996-9732. ; 45:9, s. 87-94
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Tidskriftsartikel (refereegranskat)abstract
- Seven regions with coastal eutrophication problems in the Baltic Sea, including the Kattegat, constitute the BERNET project (Baltic Eutrophication Regional Network). To counteract eutrophication and associated severe biological conditions the countries around this large brackish water body must all cooperate. The regions are characterized by large differences in land use, e.g. agricultural intensity, and losses of retention capacity in the catchments due to wetland reclamation. Initially it has been necessary to identify nutrient sources - especially nitrogen - and technical, economical and even administrative obstacles to initiate eutrophication management measures. Nitrogen retention in different types of wetlands in the Baltic Sea Region has been analysed. The wetlands generally have a positive effect on reduced nitrogen transport to aquatic environments and it is generally accepted that measures leading to decreased losses of nutrients to the aquatic environment must be combined with measures leading to increased retention of nutrients in catchments. Data analysed in the BERNET project show that the potential for such a measure is large. Therefore, conservation and restoration initiatives for wetlands is an essential part of the work in the BERNET project. Wetlands have been drained or totally eliminated due to intensive agriculture in some regions while large scale rehabilitation of wetlands occurs in regions with less intensive agriculture. Based on land use data from the seven regions, the working group for wetland management within the BERNET project has identified the possible use of wetlands as building blocks as a contribution to the management of the Baltic Sea eutrophication. Several recommendations are presented on the wise use of existing and constructed wetlands for water quality management in relation to non-point nutrient pollution.
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| 2. |
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| 3. |
- Zurauskiene, N., et al.
(författare)
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Semiconductor nanostructures for infrared applications
- 2004
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Ingår i: Functional Nanomaterials For Optoelectronics And Other Applications. - : Trans Tech Publications Inc.. ; , s. 99-108
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Konferensbidrag (refereegranskat)abstract
- The results of time-resolved photo luminescence (TRPL) and optically detected microwave resonance (ODMR) spectroscopy investigations of semiconductor quantum dots and quantum wells are presented. The ODMR spectra of InAs/GaAs QDs were detected via modulation of the total intensity of the QDs emission induced by 95 GHz microwave excitation and the exciton fine structure was studied. Very long life times (up to 10 ns) of photoexcited carriers were observed in this system using TRPL at low temperatures and excitation intensities promising higher responsitivity of such QDs for infrared photodetector development. The effects of proton and alpha particles irradiation on carrier dynamics were investigated on different InGaAs/GaAs, InAlAs/AlGaAs and GaAs/AlGaAs QD and QW systems. The results showed that carrier lifetimes in QDs are much less affected by proton irradiation than that in QWs. A strong influence of irradiation on PL intensity was observed in multiple QWs after high-energy alpha particles irradiation.
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