Avancerad sökning

Visar resultat 11 - 15 av 93 avhandlingar som matchar ovanstående sökkriterier.

1. 11. Numerical Analysis of Heat Transfer and Fluid Flow in Heat Exchangers with Emphasis on Pin Fin Technology

   Författare :Hamid Nabati; Jafar Mahmoudi; Dan Loyd; Mälardalens högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; Heat exchanger; Pin fin technology; Cooling system; Power transformers; CO2; Energy- and Environmental Engineering; energi- och miljöteknik;

   Sammanfattning : One of the most important industrial processes is heat transfer, carried out by heat exchangers in single and multiphase flow applications. Despite the existence of well-developed theoretical models for different heat transfer mechanisms, the expanding need for industrial applications requiring the design and optimization of heat exchangers, has created a solid demand for experimental work and effort. LÄS MER

3. 12. Carbon exchange in boreal ecosystems: upscaling and the impacts of natural disturbances

   Författare :Julia Kelly; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Carbon fluxes; CH4; Climate change; CO2; Drought; Ecosystem respiration; Forest; Peatland; Remote sensing; Temperature; Thermal camera; UAV; Wildfire;

   Sammanfattning : Boreal forests and peatlands are globally significant carbon stores but they are threatened by rising air temperatures and changes in precipitation regimes and the frequency of natural disturbances. Predicting how the boreal biome will respond to climate change depends on being able to accurately model and upscale the greenhouse gas fluxes between these ecosystems and the atmosphere. LÄS MER

4. 13. Satistical Modelling Of CO2 Exchange Between Land And Atmosphere : Using Stochastic Optimisation And Gaussian Markov Random Fields

   Författare :Unn Dahlén; Spatio-Temporal Stochastic Modelling Group; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gaussiska Markovfält; Stokastisk optimering; CO2-flöden; Spatial statistik; Stochastic Optimisation; Gaussian Markov Random Fields; Atmospheric inverse modelling; Spatial statistics; Computational statistics;

   Sammanfattning : This thesis focuses on the development and application of efficient mathematicaltools for estimating and modelling the exchange of carbon dioxide (CO2) between the Earth and its atmosphere; here referred to as the global CO2 surface flux.There are two main approaches for estimating the CO2 flux: Processed based(bottom-up) modelling and atmospheric inversion (top-down) modelling. LÄS MER

5. 14. How do metamorphic fluids move through rocks? : An investigation of timescales, infiltration mechanisms and mineralogical controls

   Författare :Barbara I. Kleine; Alasdair D. L. Skelton; John C. Schumacher; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Metamorphic fluid flow; fluid-rock interaction; fluid infiltration mechanisms; fluid flux rates; thermodynamic modeling; reaction front propagation; fluid flux calculation; Geology; geologi;

   Sammanfattning : This thesis aims to provide a better understanding of the role of mountain building in the carbon cycle. The amount of CO2 released into the atmosphere due to metamorphic processes is largely unknown. LÄS MER

7. 15. Forests and Greenhouse gases. Fluxes of CO2, CH4 and N2O from drained forests on organic soils

   Författare :Karin von Arnold; Leif Klemedtsson; Mats Nilsson; Björn Hånell; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Greenhouse gases; GHG; fluxes of CO2; CH4; drained forests; organic soils; Skogsbotanik; miljöaspekter; växthusgaser; Water in nature and society; Vatten i natur och samhälle;

   Sammanfattning : One of the largest environmental threats believed to be facing us today is global warming due to the accumulation of green house gases (GHG). The concentrations of GHG in the atmosphere are a result of the net strength of different sinks and sources. LÄS MER