Sökning: "zone model"

Visar resultat 1 - 5 av 419 avhandlingar innehållade orden zone model.

  1. 1. Effect of Hyporheic Exchange on Conservative and Reactive Solute Transport in Streams Model Assessments Based on Tracer Tests

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Karin Jonsson; Uppsala universitet.; [2003]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; conservative; hyporheic exchange; model; reactive; retention; solute; sorption kinetics; stream transport; temporal moments; tracer experiment; Geovetenskap; NATURAL SCIENCES Earth sciences; NATURVETENSKAP Geovetenskap; Sedimentology; sedimentologi;

    Sammanfattning : Understanding of the processes affecting solute transport in flowing water is important for the possibility to predict the evolution with time of polluted stream systems. This thesis presents tracer experiment methodology and model developments for solute transport in streams, with special focus on retention processes and their effect on solute stream transport. LÄS MER

  2. 2. The Effective Convectivity Model for Simulation and Analysis of Melt Pool Heat Transfer in a Light Water Reactor Pressure Vessel Lower Head

    Detta är en avhandling från KTH : KTH

    Författare :Chi Thanh Tran; KTH.; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; light water reactor; hypothetical severe accident; accident progression; accident scenario; core melt pool; heat transfer; turbulent natural convection; heat transfer coefficient; phase change; mushy zone; crust; lower plenum; analytical model; effective convectivity model; CFD simulation; TECHNOLOGY Engineering mechanics Mechanical and thermal engineering Thermal energy engineering; TEKNIKVETENSKAP Teknisk mekanik Mekanisk och termisk energiteknik Termisk energiteknik;

    Sammanfattning : Severe accidents in a Light Water Reactor (LWR) have been a subject of intense research for the last three decades. The research in this area aims to reach understanding of the inherent physical phenomena and reduce the uncertainties in their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors, and to evaluation of the proposed accident management schemes for mitigating the consequences of severe accidents. LÄS MER

  3. 3. Development, validation and application of an effective convectivity model for simulation of melt pool heat transfer in a light water reactor lower head

    Detta är en avhandling från Stockholm : KTH

    Författare :Chi Thanh Tran; KTH.; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; light water reactor; hypothetical severe accident; accident progression; accident scenario; core melt pool; heat transfer; turbulent natural convection; heat transfer coefficient; phase change; mushy zone; crust; lower plenum; analytical model; effective convectivity model; CFD simulation.; NATURAL SCIENCES Physics Other physics; NATURVETENSKAP Fysik Övrig fysik;

    Sammanfattning : Severe accidents in a Light Water Reactor (LWR) have been a subject of the research for the last three decades. The research in this area aims to further understanding of the inherent physical phenomena and reduce the uncertainties surrounding their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors. LÄS MER

  4. 4. Model Based Optimization of a Complete Diesel Engine/SCR System

    Detta är en avhandling från Division of Combustion Engines, Lund Institute of Technology

    Författare :Claes Ericson; Lunds universitet.; Lund University.; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MPC; model based optimization; real time models; model based control; SCR; optimization; EGR;

    Sammanfattning : Achieving upcoming emissions legislation (Euro VI) for heavy trucks is a serious challenge for the manufacturers. Apart from the increasingly strict limits on nitrogen oxides (NOx) and particulate emissions (PM), the limited amount of fossil fuels as well as alarming climate changes simultaneously drives the demand for low CO2 emissions. LÄS MER

  5. 5. Investigating the parameters that influence the behaviour of natural iron ores during the iron production process

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Abraham Judah Bumalirivu Muwanguzi; KTH.; [2013]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; natural iron ore; iron production; characterization; physical and metallurgical properties; sinter; pellet; direct reduction; low temperature degradation; sample weight; sample positioning; microstructure; reduction degree; solid conversion; Volumetric Model; Grain Model; Random Pore Model; Muko; Uganda;

    Sammanfattning : In the iron production processes, sinters and pellets are mostly used as raw materials due to their consistency with respect to physical and chemical properties. However, natural iron ores, as mined, are rarely used directly as a feed material for iron processing. LÄS MER