Search for dissertations about: "iron cycling"

Showing result 1 - 5 of 41 swedish dissertations containing the words iron cycling.

2. 1. Varved lake sediments and diagenetic processes

   Author : Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

   Abstract : 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. READ MORE

4. 2. Iron in the Lena River basin, NE Russia : Insights from microscopy, spectroscopy and isotope analysis

   Author : Catherine Hirst; Carl-Magnus Mörth; Per Andersson; Mats Erik Åström; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; iron; reactivity; isotopes; permafrost; river; Arctic; Marine Geology; maringeologi;

   Abstract : 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. READ MORE

5. 3. Iron Based Materials for Positive Electrodes in Li-ion Batteries : Electrode Dynamics, Electronic Changes, Structural Transformations

   Author : Andreas Blidberg; Fredrik Björefors; Torbjörn Gustafsson; Carl Tengstedt; Miran Gaberšček; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Li-ion; batteries; electrochemistry; iron; LiFeSO4F; Li2FeP2O7; PEDOT; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

   Abstract : Li-ion battery technology is currently the most efficient form of electrochemical energy storage. The commercialization of Li-ion batteries in the early 1990’s revolutionized the portable electronics market, but further improvements are necessary for applications in electric vehicles and load levelling of the electric grid. READ MORE

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

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

   Abstract : 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. READ MORE

7. 5. Causes and consequences of Gonyostomum semen blooms

   Author : Karla Münzner; Eva S. Lindström; Lars J. Tranvik; Gesa A. Weyhenmeyer; Silke Langenheder; Ann-Kristin Bergström; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Gonyostomum semen; algal blooms; brown water lakes; lake browning; iron; dissolved organic carbon DOC ; carbon cycling; pCO2; CO2; organic matter; sedimentation; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

   Abstract : Aquatic ecosystems provide essential ecosystem services, but are also highly vulnerable to global change. Climate change, eutrophication and browning, for example, collectively drive the increase of harmful algal blooms in freshwaters. READ MORE