Sökning: "platinum"

Visar resultat 21 - 25 av 294 avhandlingar innehållade ordet platinum.

  1. 21. Requirement and Availability of Scarce Metals for Fuel-Cell and Battery Electric Vehicles

    Författare :Ingrid Råde; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; metal requirement; sustainability; fuel cells; batteries; platinum; metal scarcity; resources; electric vehicles; metal availability; industrial ecology;

    Sammanfattning : Battery and fuel-cell electric vehicles (EVs) are considered as a means to meet some of the environmental and resource challenges of todays road vehicle system. EVs have the potential for zero tailpipe emissions as well as an energy efficiency higher than internal combustion engine vehicles and they can be flexible concerning primary energy source. LÄS MER

  3. 22. Catalysis for Lean NOx Reduction - Aspects of Catalyst Synthesis and Surface Acidity

    Författare :Hanna Härelind Ingelsten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lean NOx reduction; silica; alumina; FTIR; surface acidity; model catalysts; platinum; HZSM-5; w o microemulsion; aluminum-silicate; hydrocarbon;

    Sammanfattning : From both economic and environmental perspectives it is desirable to reduce the consumption of fossil fuels. One route to increase the fuel efficiency for vehicles is operation in oxygen excess. However, a major problem with this technique is the lean environment, which obstructs catalytic reduction of nitrogen oxides (NOx) to harmless nitrogen. LÄS MER

  4. 23. Laboratory and Stellar Spectra in High Resolution: Studies of Fe, Pt and Tl in Peculiar Stars

    Författare :Gabriele Kalus; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-resolution spectroscopy; hyperfine structure; peculiar stars; iron; platinum; lead; upsilon Sagittarii; HR7775; chi Lupi; isotope shift; Atomic and molecular physics; Atom- och molekylärfysik; Fysicumarkivet A:1997:Kalus;

    Sammanfattning : The near-infrared spectrum of upsilon Sagittarii has been registered using the SOFIN high resolution spectrometer on the Nordic Optic Telescope, La Palma. For the first time 4f-5g transitions of Fe II in any astrophysical spectrum have been identified. LÄS MER

  5. 24. Thin-Film Electrocatalysts for Polymer Electrolyte Fuel Cells - Activity, Durability and Proton Conduction

    Författare :Björn Wickman; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nafion; thin film evaporation; PEMFC; platinum; titanium oxide; cathode; fuel cell; oxygen reduction reaction; electrocatalyst; proton conduction; model systems;

    Sammanfattning : The polymer electrolyte membrane fuel cell (PEMFC) is a potential technology for future energy conversion in sustainable energy systems. By using hydrogen from renewable energy sources and oxygen from the air, the fuel cell produces electricity with water as the only exhaust. LÄS MER

  7. 25. Materials for High-Temperature Catalytic Combustion

    Författare :Anders Ersson; KTH; []
    Nyckelord :catalytic combustion; catalyst materials; palladium; platinum; bimetallic; garnet; spinel; hexaaluminate; deactivation; sulphur; poisoning; diesel; methane; hydrocarbons;

    Sammanfattning : Catalytic combustion is an environmentally friendlytechnique to combust fuels in e.g. gas turbines. Introducing acatalyst into the combustion chamber of a gas turbine allowscombustion outside the normal flammability limits. LÄS MER