Visar resultat 1 - 5 av 1348 avhandlingar innehållade ordet nitrogen.
1. Marine nitrogen fixation : Cyanobacterial nitrogen fixation and the fate of new nitrogen in the Baltic Sea
Sammanfattning : Biogeochemical processes in the marine biosphere are important in global element cycling and greatly influence the gas composition of the Earth’s atmosphere. The nitrogen cycle is a key component of marine biogeochemical cycles. LÄS MER
Sammanfattning : In most ecosystems, nitrogen is a scarce and growth-limiting nutrient. Natural and anthropogenic processes convert unreactive atmospheric dinitrogen (N2) into reactive, bioavailable, nitrogen. LÄS MER
Sammanfattning : Addition of fertiliser nitrogen (N) in crop production increases yields and protein contents, but all is not taken up by the crop. Instead, some of the N is lost to air and waters, contributing e.g. to climate change, stratospheric ozone depletion, eutrophication and acidification. LÄS MER
4. Biological nitrogen fixation : the effect of irridiated nitrogen gas on nitrogen fixation by Azotobacter
Sammanfattning : .... LÄS MER
Sammanfattning : The Baltic Sea in northern Europe is a brackish water body where eutrophication is considered a serious problem, partly as a result of high nitrogen load from rivers. This thesis includes statistical analysis of nitrogen behaviour in 55 small catchments. The results were used for further development of a dynamic model (HBV-N). LÄS MER