Sökning: "natural sources"
Visar resultat 6 - 10 av 1606 avhandlingar innehållade orden natural sources.
6. Geographical Distribution of Disasters Caused by Natural Hazards in Data-scarce Areas : Methodological exploration on the Samala River catchment, Guatemala
Sammanfattning : An increasing trend in both the number of disasters and affected people has been observed, especially during the second half of the 20th century. The physical, economic and social impact that natural hazards have had on a global scale has prompted an increasing interest of governments, international institutions and the academia. LÄS MER
7. Sources, transport and fate of perfluoroalkyl acids in the atmosphere
Sammanfattning : Perfluoroalkyl acids (PFAAs) are man-made chemicals which have been observed in the global environment, even in locations far away from where they are emitted. These persistent substances are taken up in humans and biota and may have toxic effects. LÄS MER
8. Tracing and apportioning sources of dioxins using multivariate pattern recognition techniques
Sammanfattning : High levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in edible fish in the Baltic Sea have raised health concerns in the Baltic region and the rest of Europe. Thus, there are urgent needs to characterize sources in order to formulate effective mitigation strategies. LÄS MER
9. Aerosol Particle Sources Affecting the Swedish Air Quality at Urban and Rural Level
Sammanfattning : During the last decades anthropogenic aerosol particles have attracted much attention due to their adverse health effects and their influence of climate change, and in Sweden, there are mainly three aerosol sources that affect the air quality; domestic wood combustion, traffic, and long distance transport, which includes new particle formation. This work concerns the characterization of these sources and an estimate of how much they contribute to the aerosol particle number (ToN) and mass concentrations (PM) in Swedish cities and at background locations. LÄS MER
10. Compact Soft X-Ray Microscopy : Sources, Optics and Instrumentation
Sammanfattning : This thesis describes the development of a sub-60-nm full-period resolution compact soft x-ray microscope operating in the water-window region (2.3-4.4 nm). Soft x-ray water-window microscopy is a powerful technique for high-resolution imaging of organic materials exploiting the natural contrast mechanism between carbon and oxygen, cf. LÄS MER