Sökning: "iron cycling"
Visar resultat 1 - 5 av 31 avhandlingar innehållade orden iron cycling.
- Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap
Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER
2. Iron in the Lena River basin, NE Russia Insights from microscopy, spectroscopy and isotope analysisDetta är en avhandling från Stockholm : Department of Geological Sciences, Stockholm University
Sammanfattning : Iron is an important mediator of biotic and abiotic processes on the Earth’s surface, being an electron acceptor in organic matter degradation, a surface for organic matter and trace element adsorption, and a required element for enzymatic processes during primary production. Yet, the role of iron as a mediator of carbon and trace element cycling in high latitude, permafrost-dominated regions remains poorly investigated. LÄS MER
- Detta är en avhandling från STOCKHOLM : KTH Royal Institute of Technology
Sammanfattning : An exhaust manifold of a truck engine is subjected to tough conditions. As the truck is started, operated and shut down, it becomes subjected to thermal cycling up to around 800°C. At such high temperatures, corrosion, fatigue and creep are active degradation mechanisms. LÄS MER
4. Degradation Mechanisms of Heat Resistant Steel at Elevated Temperatures In an Iron Ore Pelletizing IndustryDetta är en avhandling från Luleå : Luleå University of Technology
Sammanfattning : This thesis focuses on the different degradation mechanisms of the stainless steel in a travelling grate in a Grate-Kiln iron ore pellet indurator. The travelling grate is a conveyor belt that transports green-body pellets to a rotary kiln while the pellets are being dried and pre-heated to a temperature of 900-1100 °C by recycled hot air. LÄS MER
- Detta är en avhandling från Luleå : Luleå University of Technology
Sammanfattning : High nitrogen effluents from mine sites is an environmental issue which has received relatively little attention historically. In recent years a number of studies have showed the environmental effects of high nitrogen discharge to natural water bodies, which include local eutrophication, high risk of acute reducing conditions and changed species composition in the receiving waters. LÄS MER