Sökning: "conductivity"

Visar resultat 1 - 5 av 895 avhandlingar innehållade ordet conductivity.

  1. 1. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

    Författare :Joakim Nyman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

    Sammanfattning : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. LÄS MER

  3. 2. Theoretical Studies on Electronic Structure, Spectra and Conductivity of Pristine and Alkali Doped Polyacetylene

    Författare :Lucía Mercedes Rodrigues Monge; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; theoretical calculations; electron transfer; conductivity; polyacetylene; alkali metal; ab-initio methods; charge transport; semiempirical methods; doping;

    Sammanfattning : The present thesis is a theoretical investigation of the electronic properties of linear polyenes to get an insight into conductive phenomena in pristine and doped polyacetylene. Conductivity in polyacetylene is a complex phenomena and cannot be treated within simple band models. LÄS MER

  4. 3. Hydraulic Conductivity of Saturated Sand-Bentonite mixtures

    Författare :Malin Sundsten; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quarry sand; design; bentonite; landfill barrier; field tests; dry density; foundry green sand; laboratory tests; hydraulic conductivity;

    Sammanfattning : The implementation of the EC directive concerning landfill liners and covers sets stricter technical and environmental requirements for landfill barriers. It is therefore essential to identify suitable materials that fulfil these requirements. LÄS MER

  5. 4. Understanding Ionic Conductivity in Crystalline Polymer Electrolytes

    Författare :Daniel Brandell; Josh Thomas; Torbjörn Gustafsson; Peter G. Bruce; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Polymer electrolyte; molecular dynamics; conductivity mechanism; aliovalent anion substitution; smectic; nematic; polymer chain length; Kemi; Chemistry; Kemi;

    Sammanfattning : Polymer electrolytes are widely used as ion transport media in vital applications such as energy storage devices and electrochemical displays. To further develop these materials, it is important to understand their ionic conductivity mechanisms. LÄS MER

  7. 5. Thermal Conductivity of Cast Iron: Influences of Microstructure on the Thermal Conductivity of Cast Iron

    Författare :Daniel Holmgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; EBSD; Laser Flash Technique; Modelling; Spheroidal Graphite; Lamellar Graphite; Primary Austenite; Compacted Graphite; Pearlite; Ferrite; Thermal Conductivity;

    Sammanfattning : The thermal transport properties of cast iron are important in high temperature applications,where the temperatures should be kept low and the thermal gradients within the componentsmall. Dimensional and microstructural changes, thermally induced stresses and even failuremight be catastrophic consequences of intense and/or unevenly distributed temperatures. LÄS MER