Sökning: "Ivars Neretnieks"

Visar resultat 6 - 10 av 12 avhandlingar innehållade orden Ivars Neretnieks.

1. 6. Solute Transport in Fractured Rocks : The Effect of Stagnant Water Zones and Velocity Dispersion

   Författare :Pirouz Shahkarami; Longcheng Liu; Ivars Neretnieks; Luis Moreno; Klaus-Peter Kröhn; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Channel network concept; radionuclide transport; stagnant water zones; velocity dispersion; modeling and simulation; Chemical Engineering; Kemiteknik;

   Sammanfattning : The focus of this thesis is on the development of new models to improve our understanding of radionuclide transport in the repository “far-field” in fractured rocks. The proposed models contribute to the channel network concept and describe the recently developed models with stagnant water zones (STWZs) and channels with variable aperture allowing to consider their possible impacts on the overall transport of radionuclides in fractured rocks. LÄS MER

3. 7. Modelling long-term redox processes and oxygen scavenging in fractured crystalline rocks

   Författare :Magnus Sidborn; Ivars Neretnieks; Chin-Fu Tsang; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Redox chemistry; hydrogeological model; groundwater chemistry; mineral interaction; Chemical engineering; Kemiteknik;

   Sammanfattning : Under de senaste decennierna har i många länder, inkluderat Sverige, långt gångna planer utvecklats för ett djupförvar av högaktivt kärnavfall. Som en del i det svenska förvarskonceptet skall avfallet inneslutas i kopparkapslar som omslutes av återfyllnadsmaterial med mycket låg genomsläpplighet av vatten. LÄS MER

4. 8. Long-term metal retention processes in a peat bog : Field studies, data and modelling

   Författare :Kristina Syrovetnik; Ivars Neretnieks; Bert Allard; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Peat; heavy metals distribution; sequential extraction; binding mechanisms; modelling; metal sulphide oxidation; aqueous composition; sorption; humic substances; ferric oxyhydroxide; Chemical engineering; Kemiteknik;

   Sammanfattning : The study was inspired by the need to assess long-term metal retention in municipal solid waste (MSW) landfills. The long-term processes in landfills are poorly known due to the relatively short time that such landfills have been in existence. Natural analogues where similar metal binding processes could be expected were therefore sought for. LÄS MER

5. 9. A weighted correlation approach of the density functional theory for an inhomogeneous fluid at an interface

   Författare :Zhao Wang; Longcheng Liu; Ivars Neretnieks; Małgorzata Borówko; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inhomogeneous fluid; interface; density functional theory;

   Sammanfattning : This doctoral thesis presents a newly developed density functional theory (DFT), i.e., the weighted correlation approach (WCA), to study the structural and thermodynamic properties of an inhomogeneous fluid at an interface. LÄS MER

7. 10. Water density impact on water flow and mass transport in rock fractures

   Författare :Helen Winberg-Wang; Longcheng Liu; Ivars Neretnieks; Andrew Frampton; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tracer experiments; solute transport in fractured rock; advection-diffusion experiments; repositories; equivalent flowrate.; Spårämnesexperiment; ämnestransport i bergssprickor; advektion och diffusionsexperiment; slutförvar; ekvivalent flöde.;

   Sammanfattning : One way of taking care of spent nuclear fuel is to place it in a geological repository. In Sweden, a three-barrier system is planned. The system is based on encapsulating the fuel in copper canisters. These are surrounded by bentonite clay and buried under 500 m of bedrock. LÄS MER