Sökning: "organic geochemistry"

Visar resultat 1 - 5 av 92 avhandlingar innehållade orden organic geochemistry.

1. 1. Origin of organic compounds in fluids from ultramafic-hosted hydrothermal vents of the Mid-Atlantic Ridge

   Författare :Cécile Konn; Nils Holm; Jean-Luc Charlou; Barbara Sherwood Lollar; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Serpentinisation; hydrocarbons; organic compounds; ultramafic; hydrothermal; geochemistry; origin of life; Other earth sciences; Övrig geovetenskap; Other chemistry; Övrig kemi; Exogenous geochemistry; Exogen geokemi; geokemi; Geochemistry;

   Sammanfattning : Natural gas, primarily methane (CH4), is produced in substantial amounts in ultramafic-hosted hydrothermal systems. These systems could also generate oil (heavier hydrocarbons) and the first building blocks of life (prebiotic molecules). In the presence of iron bearing minerals, serpentinisation reactions generate H2. LÄS MER

3. 2. Export and sources of organic carbon in the Lena River basin, Northeastern Siberia

   Författare :Liselott Kutscher; Carl-Magnus Mörth; Per Andersson; Don Porcelli; Peter Raymond; Sebastian Sobek; Stockholms universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. Low Molecular Weight Organic Acids and Their Aluminium Complexes in Forest Soils

   Författare :Patrick van Hees; F. C. Ugolini; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The significance of low molecular weight (LMW) organic acids and their aluminium (Al) complexes in soil solutions of podzolized soils was examined. Methods for the analysis of these compounds and complexes were developed, and the impact of these substances on the weathering and podzolization processes was studied. LÄS MER

5. 4. Nitrogen Cycling at Cold Climate Mine Sites in Northen Sweden

   Författare :Lino Nilsson; Anders Widerlund; Anders Lundqvist; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen; Mining; Cycling; nutrients; Isotopes; Nitrogen-model; modelling; numerical-modelling; Isotope-tracing; Tracing; Isotope; geochemistry; Applied Geology; Tillämpad geologi;

   Sammanfattning : High nitrogen discharge from mining sites has been an environmental issue that has been closely studied in the recent years. The environmental effects of high nitrogen discharge are mainly eutrophication, but can also lead to changed species composition and algae blooms. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER