Sökning: "natural sources"
Visar resultat 21 - 25 av 1606 avhandlingar innehållade orden natural sources.
21. Chemical characteristics of atmospheric aerosols : the influence of natural and man-made sources and sinks
Sammanfattning : In order to improve the understanding of the climatic and environmental effects of atmospheric aerosol particles, knowledge about their sources, sinks, chemical and physical characteristics as well as transportation in the atmosphere is needed. This thesis examines the water-soluble chemical characteristics of aerosol particles and precipitation and their interaction with trace gases. LÄS MER
22. Fluoride in surface water and groundwater in southeast Sweden : sources, controls and risk aspects
Sammanfattning : The aim of this thesis is to determine the sources, controls and risk aspects of fluoride in surface water and groundwater in a region of southeastern Sweden where the fluorine-rich 1.45 Ga circular Götemar granite (5 km in diameter) crops out in the surrounding 1.8 Ga granites and quartz monzodiorites (TIB rocks). LÄS MER
23. Carbon in Boreal Streams : Isotopic Tracing of Terrestrial Sources
Sammanfattning : The boreal biome comprises vast areas of coniferous forests, dotted with millions of peatlands. Plants harbouring these ecosystems fix CO2 from the atmosphere, which is later incorporated into the vegetation biomass and subsequently buried in soils. LÄS MER
24. Unraveling the importance of solid and adsorbed phase mercury speciation for methylmercury formation, evasion and bioaccumulation
Sammanfattning : Monomethylmercury, MeHg, is formed under anoxic conditions in waters, sediments and soils and then bioaccumulated and biomagnified in aquatic food webs, negatively effecting both human and wildlife health. It is generally accepted that precipitation of mercury, Hg, and adsorption of Hg to e.g. LÄS MER
25. Materials for future power sources
Sammanfattning : Proton exchange membrane fuel cells and lithium polymer batteries are important as future power sources in electronic devices, vehicles and stationary applications. The development of these power sources involves finding and characterising materials that are well suited r the application. LÄS MER