Search for dissertations about: "Helium emissions"

Found 4 swedish dissertations containing the words Helium emissions.

  2. 1. Injection and Combustion of Alternative Fuels in Spark Ignited Direct Injection Engines

    Author : Lars Christian Riis Johansen; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gas fuel; direct injection; E85; stratified combustion; spark ignition; alternative fuels; optical measurements;

    Abstract : Increasingly stringent vehicle emission legislation necessitates increasingly efficient combustion engines. The use of direct injection in spark ignited engines improves engine efficiency and reduces CO2 emissions. READ MORE

  4. 2. Spark Ignition Combustion of Direct Injected Alternative Fuels

    Author : Lars Christian Riis Johansen; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spark ignition; optical diagnostics; internal combustion engine; stratified combustion;

    Abstract : Several technologies and modifications exist to increase the fuel efficiency of passenger vehicles in general and spark ignition engines in particular. Combining a spark ignition engine with an electric drive system in hybrid powertrain and thermodynamic cycle improvements are two such approaches with the potential to greatly reduce fuel consumption. READ MORE

  5. 3. Luminescence Properties of ZnO Nanostructures and Their Implementation as White Light Emitting Diodes (LEDs)

    Author : Naveed ul Hassan Alvi; Magnus Willander; Omer Nour; Vladimir V. Mitin; Linköpings universitet; []
    Keywords : Nanotechnology; Zinc oxide; nanostructures; luminescence; LEDs; color rendering; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : In this thesis, luminescence properties of ZnO nanostructures (nanorods, nanotubes, nanowalls and nanoflowers) are investigated by different approaches for possible future application of these nanostructures as white light emitting diodes. ZnO nanostructures were grown by different growth techniques on different p-type substrates. READ MORE

  6. 4. Radiative Properties of Rare Earth Elements - Free and Bound in Crystals

    Author : Huailiang Xu; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Laser Spectroscopy; Upconversion; Lifetimes; Atomic and molecular physics; Atom- och molekylärfysik; Laser technology; Laserteknik; Rare earth Elements; Fysicumarkivet A:2004:Xu;

    Abstract : This thesis is devoted to fundamental aspects, and to spectroscopic applications of radiative properties in free atoms and ions, as well as in ions doped into crystals. Using the time-resolved laser-induced fluorescence technique, measurements of radiative lifetimes for rare earth elements have been performed in neutral Pr, Nd, Tm, and in singly ionized Sm, Er, Nd, Tm, Yb, as well as in doubly ionized Tm and Tb ions. READ MORE