Sökning: "dissolved oxygen"

Visar resultat 1 - 5 av 136 avhandlingar innehållade orden dissolved oxygen.

1. 1. The Impact of Dissolved Matter on Fiberline Processes

   Författare :Caroline Wilke; Ulf Germgård; Niclas Andersson; Juha Fiskari; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bleach plant control; Carbonate; Carryover; Chlorine dioxide bleaching; COD; Dissolved lignin; Dissolved matter; Fiberline control; Filtrate; Hexenuronic acid; Hydrogen peroxide bleaching; Kappa number; Oxygen delignification; Wash loss; Chemical Engineering; Kemiteknik;

   Sammanfattning : The impact of dissolved matter on the performance of four fiberline process stages was investigated: oxygen delignification, hot acid treatment, chlorine dioxide bleaching, and hydrogen peroxide reinforced alkaline extraction. In particular the impact on delignification due to dissolved lignin was studied. LÄS MER

3. 2. Influence of resuspension on sediment-water solute exchange and particle transport in marine environments

   Författare :Elin Almroth Rosell; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; resuspension; benthic fluxes; oxygen; dissolved inorganic carbon; nutrients; dissolved iron and manganese; in situ chambers; benthic lander; organic matter transport; ecological modeling; Gothenburg Archipelago; Gulf of Finland; Baltic Sea; Loch Creran; Scotland;

   Sammanfattning : Marine sediments contain a large pool of nutrients, which if released would contribute to increased eutrophication, in spite of decreased nutrient loads from land and atmosphere. Resuspension is a process, which might influence the release of nutrients from the sediment to the overlying water. LÄS MER

4. 3. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

   Författare :Anders Tengberg; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

   Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER

5. 4. Benthic fluxes of biogenic elements in the Baltic Sea : Influence of oxygen and macrofauna

   Författare :Nils Ekeroth; Sven Blomqvist; Per OJ Hall; Bjørn Sundby; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sediment biogeochemistry; Bioturbation; Benthic nutrient fluxes; Bottom water oxygenation; Box corer; Sediment sampling; Marine Ecology; marin ekologi;

   Sammanfattning : This thesis investigates how benthic fluxes of phosphorus (P), nitrogen (N), and silicon (Si) change upon oxygenation of anoxic soft bottoms in the brackish, eutrophicated Baltic Sea. Direct measurements in situ by benthic landers demonstrated that fluxes of dissolved inorganic P (DIP) from anoxic bottom sediments in the Eastern Gotland Basin are higher than previously thought (Paper I). LÄS MER

7. 5. The Baltic Sea marine system - human impact and natural variations

   Författare :Erik Gustafsson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; modelling; salinity; oxygen; nutrients; eutrophication; acidification; climate;

   Sammanfattning : The environmental state of the Baltic Sea system is influenced by both natural and anthropogenic factors. Water exchange with the adjacent ocean and within the system depend on large-scale atmospheric circulation and properties of the straits separating the different sub-basins. LÄS MER