Search for dissertations about: "spatial heterogeneity"

Showing result 21 - 25 of 173 swedish dissertations containing the words spatial heterogeneity.

2. 21. Hydrodynamic control of retention in heterogeneous aquifers and fractured rock

   Author : Hua Cheng; Vladimir Cvetkovic; Chin-Fu Tsang; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aquifer; Fracture; groundwater; First-order solution; Monte-Carlo simulation; Nu-clear waste; Heterogeneity; Retention processes; Matrix diffusion; Prediction; Evaluation; Travel time; Flow rate; ; Water engineering; Vattenteknik;

   Abstract : In this thesis, fluid flow and solute transport in heterogeneous aquifers and particularly in frac-tured rock have been investigated using Lagrangian Stochastic Advective-Reaction (LaSAR) framework. The heterogeneity of the aquifer structure or fracture configuration, as well as the various reaction/retention processes have been considered in the modelling approach. READ MORE

4. 22. Get a grip on chaos : Tailored measures for complex systems on surfaces

   Author : Sascha Firle; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; complex systems; chaos; predator prey; movement models; functional response; spatial heterogeneity; topological dynamics; braid template; homoclinic bifurcations; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

   Abstract : Complex systems are ubiquitous in physics, biology and mathematics. This thesis is concerned with describing and understanding complex systems. Some new concepts about how large systems can be viewed in a lower dimensional framework are proposed. The systems presented are examples from ecology and chemistry. READ MORE

5. 23. Stability and complexity of ecosystems - Global interaction constraints, landscape and extinctions

   Author : Susanne Pettersson; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Complexity; Collapse; Stability; Ecosystems; Extinctions; Population dynamics; spatial heterogeneity; Dynamical systems; dispersal;

   Abstract : Human society's expansion and demand for both biotic and abiotic natural resources exert a large pressure on ecosystems around the globe. Ecosystems are complex networks of species interacting with each other and their physical surroundings. READ MORE

6. 24. Unsaturated Solute Transport in a Semiarid Catchment - Nonlinear Analyses and Modelling

   Author : Pernilla Öhrström; Avdelningen för Teknisk vattenresurslära; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; teknisk geografi; Hydrogeologi; teknisk geologi; unsaturated zone; Hydrogeology; geographical and geological engineering; solute transport; scaling; soils; semiarid regions; heterogeneity; preferential flow; fractals;

   Abstract : Unsaturated solute transport is highly variable and therefore difficult to predict. In semi-arid areas, where water resources are limited, the presence of macropores is of great importance for crop production. The bromide ion (Br-) and dye tracers are useful for studies of water movement. READ MORE

7. 25. Process Models for CO2 Migration and Leakage : Gas Transport, Pore-Scale Displacement and Effects of Impurities

   Author : Farzad Basirat; Auli Niemi; Karsten Jensen; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geological Carbon Storage; CO2 leakage; Field experiment; Laboratory experiment design; Multi-phase flow; Heterogeneity; Wettability; Pore-scale modeling; Impurity gases; Hydrology; Hydrologi;

   Abstract : Geological Carbon Storage (GCS) is considered as one of the key techniques to reduce the rate of atmospheric emissions of CO2 and thereby to contribute to controlling the global warming. A successful application of a GCS project requires the capability of the formation to trap CO2 for a long term. READ MORE