Search for dissertations about: "Geochemistry"

Showing result 11 - 15 of 303 swedish dissertations containing the word Geochemistry.

  2. 11. A surface approach to understanding the dissolution of fluorite type materials : Implications for mineral dissolution kinetic models

    Author : José Ricardo Assunção Godinho; Sandra Piazolo; Andreas Lüttge; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; dissolution; topography; fluorite; surface; geokemi; Geochemistry;

    Abstract : Traditional dissolution models are based in the analyses of bulk solution compositions and ignore the fact that different sites of a surface dissolve at different rates. Consequently, the variation of surface area and surface reactivity during dissolution are not considered for the calculation of the overall dissolution rate, which is expected to remain constant with time. READ MORE

  4. 12. Phosphate and Arsenic Cycling under Experimental Early Proterozoic Marine Conditions

    Author : Christoffer Hemmingsson; Iain Pitcairn; Ernest Chi Fru; Per Andersson; Christophe Dupraz; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; DIP; Early Proterozoic; coprecipitation; adsorption; Iron formations; BIF; geokemi; Geochemistry;

    Abstract : Nutrient dynamics in the Archean-Paleoproterozoic oceans strongly influenced primary productivity and the rise of atmospheric O2. Reconstructing the cycling of key nutrients such as dissolved inorganic phosphate (DIP) at this time is important for our understanding of the timing, rate and extent of atmospheric oxygenation at this time. READ MORE

  5. 13. Carbon trace gas dynamics in subarctic lakes

    Author : Joachim Jansen; Patrick Crill; Andreas Lorke; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; lakes; methane; carbon dioxide; fluxes; gas transfer; proxy; climate change; geokemi; Geochemistry;

    Abstract : Northern lakes are important sources of greenhouse gases carbon dioxide and methane to the atmosphere. Emissions are expected to increase as the climate continues to warm. Even so, lake carbon budgets are currently poorly constrained. This is in part because of a limited understanding of the processes that govern the flux. READ MORE

  6. 14. Export and sources of organic carbon in the Lena River basin, Northeastern Siberia

    Author : Liselott Kutscher; Carl-Magnus Mörth; Per Andersson; Don Porcelli; Peter Raymond; Sebastian Sobek; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; organic carbon; DOC; POC; organic matter; NOM; DOM; POM; Lena River; organsikt kol; DOC; POC; organiskt material; NOM; DOM; POM; Lenafloden; geokemi; Geochemistry;

    Abstract : Permafrost areas are considered to be one of the largest terrestrial storages of carbon. In a warming climate these areas are expected to experience changes in carbon transport to rivers and the oceans due to permafrost thawing, which could enhance erosion, change water flow pathways and increase greenhouse gas emissions. READ MORE

  7. 15. Hydrogeochemical effects of hydropower regulation on river-aquifer continuum in boreal rivers

    Author : Dmytro Siergieiev; Hjalmar Laudon; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geochemistry; hyporheic zone; hydrology; riparian zone; Element transport; Lule River; Kalix RIver; Northern Sweden; Earth sciences; Applied Geology; Tillämpad geologi;

    Abstract : Hydropower infrastructure affects many large rivers worldwide, threatening riverine and coastal ecosystems by fragmenting flow, disturbing landscapes and water retention and altering sedimentation and primary production. This thesis investigated major impacts of hydropower regulation on hydrological and geochemical processes in large boreal rivers. READ MORE