Search for dissertations about: "up cycling"

Showing result 1 - 5 of 104 swedish dissertations containing the words up cycling.

2. 1. Linking distributed hydrological processes with ecosystem vegetation dynamics and carbon cycling: Modelling studies in a subarctic catchment of northern Sweden

   Author : Jing Tang; Institutionen för naturgeografi och ekosystemvetenskap; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Carbon cycling; Water cycling; Hydrological modelling; Ecosystem modelling; Subarctic ecosystems; Climate change;

   Abstract : The Arctic and Subarctic regions are of particular importance to the global climate change and are now experiencing a climate warming that is higher than the global average. Around 50% of the global soil carbon is stored in high latitude soils, especially in permafrost and peatland soils. READ MORE

4. 2. Mercury cycling in the global marine environment

   Author : Michelle Nerentorp; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; sea ice; air; seasonal and spatial variation; snow; Mercury cycling; seawater; mercury flux;

   Abstract : Mercury is a globally distributed contaminant that exists in the atmosphere in its elemental form as a stable monoatomic gas. Having a residence time of around one year in air allows it to be transported far from emission sources and end up in polar ecosystems. READ MORE

5. 3. Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems

   Author : Hélène Barthelemy; Olofsson Johan; Ellen Dorrepaal; Ann Milbau; Gough Laura; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Reindeer grazing; large herbivores; nutrient cycling; plant nutrient uptake; soil nutrient availability; arctic plant ecology; soil microbial communities; 15N stable isotopes; plant-soil interactions; plant quality; dung and urine.; Environmental Science; miljövetenskap; biology; biologi;

   Abstract : Reindeer appear to have strong positive effects on plant productivity and nutrient cycling in strongly nutrient-limited ecosystems. While the direct effects of grazing on vegetation composition have been intensively studied, much less is known about the indirect effect of grazing on plant-soil interactions. READ MORE

6. 4. Thermal Cycling, Creep- and Tensile Testing of Cast Exhaust Materials at Elevated Temperatures

   Author : Christian Öberg; Stefan Jonsson; Henrik Östling; KTH; []
   Keywords : creep; constant-load; thermal cycling; tensile test; cast materials; cast iron; exhaust materials.; Teknisk materialvetenskap; Materials Science and Engineering;

   Abstract : 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. READ MORE

7. 5. Anoxic degradation of organic matter in lakes : implications for carbon cycling and aquatic food webs

   Author : David Bastviken; Joseph M Gasol; Linköpings universitet; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Ekonsystem i vatten; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

   Abstract : Considerable evidence from laboratory studies and marine environments suggests that degradation of organic matter (OM) is restricted under anoxic conditions compared to when molecular oxygen (O2) is present. However, other studies contradict this view since they found similar OM degradation rates and bacterial growth rates under both oxic and anoxic conditions in aquatic environments. READ MORE