Sökning: "PM"

Visar resultat 1 - 5 av 305 avhandlingar innehållade ordet PM.

1. 1. Contact fatigue and crack propagation studies of sintered PM steel

   Författare :Anders Holmberg; Åsa Kassman Rudolphi; Urban Wiklund; Johan Ahlström; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tribology; PM steel; Fatigue; Crack Initiation; Crack Propagation; Material Analysis; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : Gears made of PM steel are of interest for the automotive industry because from the press/sinter route, complex geometries can be produced to near net shape with only a few processing steps while keeping the material and energy usage at a minimum. However, the PM steels of today have significant performance limitations caused by the inherent porosity which impairs the mechanical properties by acting as stress raisers in the material. LÄS MER

3. 2. Towards sustainable heavy-duty transportation : Combustion and emissions using renewable fuels in a compression ignition engine

   Författare :Maja Novakovic; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; RME; HVO; E85; methanol; ethanol; decarbonization; defossilization; heavy-duty; compression-ignition engine; ow temperature combustion; PPC; emissions; PM; particles; aerosol; OA; SOA; DOC;

   Sammanfattning : Transportation should become sustainable and available to everyone. Currently, transportation accounts for approx. one sixth of greenhouse gas (GHG) emissions globally, and heavy-duty trucks are responsible for almost 30% of that. LÄS MER

4. 3. Air Pollution Dependency on Climate Variability and Source Region : Past, Current and Future Air Pollution Scenarios over Europe

   Författare :Camilla Andersson; Hans-Christen Hansson; Christer Johansson; Joakim Langner; David Simpson; Peter Builtjes; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acidification; Air Pollution; Climate Change; Europe; Numerical Model; Emission; Eutrophication; Key region; Nitrogen Dioxide; Particulate Matter; PM; Source region; Surface Ozone; Tropospheric Ozone; Earth sciences; Geovetenskap; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : The main objectives of this thesis were to investigate the dependency of European air pollution on climate variability and emission source region. Calculations with a chemistry transport model (CTM) were conducted to investigate the influence of climate variability. LÄS MER

5. 4. Water-in-diesel emulsion and microemulsion fuels: composition, structure and effect on emissions

   Författare :Anna Lif; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NOx; microemulsion; combustion; diffusometry; alternative fuels; emission; emulsion; Fischer-Tropsch; MFC; PM; microfibrillated cellulose; NMR; surfactant; soot; diesel;

   Sammanfattning : Water-in-diesel fuels, as emulsions and microemulsions, give reduced emissions of nitrogen oxides (NOx) and particulate matter (PM) in combustion in diesel engines compared to regular diesel. These fuels can contribute to an improved local environment in densely populated areas as they can replace regular diesel in existing vehicles without any engine modification requirements. LÄS MER

7. 5. Water-in-diesel emulsion and microemulsion fuels -The effect of water on emission levels

   Författare :Anna Lif; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Combustion; Diesel; Soot; NMR; Microemulsion; PM; Emulsion; Surfactant; NOx; Diffusometry; Alternative fuels; Emission;

   Sammanfattning : Water-in-diesel emulsions are known as environmentally favourable alternatives to conventional diesel fuel. Introducing water into the combustion results in reduced emissions of the health hazardous components nitrogen oxide (NOx) and particulate matter (PM). The concept of using emulsions is advantageous as it is easy to replace regular diesel. LÄS MER