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Visar resultat 21 - 25 av 40 avhandlingar som matchar ovanstående sökkriterier.

  1. 21. Potential mechanisms for acute health effects and lung retention of inhaled particles of different origin

    Författare :Anna Klepczynska Nyström; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Background: Environmental particle exposure is known to have negative health effects. There is limited knowledge about how size and origin of particles influence these effects. There is also little known regarding the fate of ultrafine particles (particles in nanosize;< 100 nanometers in diameter) after being inhaled. LÄS MER

  3. 22. Studies of aerosol particle formation from various sources using ion and electron beam analytical techniques

    Författare :Arash Gharibi; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GUPIX; TEM; SEM; EDX; biomass combustion; traffic; road; jet droplets; film droplets; Physics; Nuclear physics; Fysik; Kärnfysik; pollution control; Environmental technology; Aerosol particles; PIXE; sources emission; tire; Arctic; Miljöteknik; kontroll av utsläpp; Fysicumarkivet A:000;

    Sammanfattning : The thesis presents the results of studies of aerosol particle formation using ion and electron beam analytical techniques. The sources of aerosol particle formation studied are the following: 1. production of primary aerosol particles in the high Arctic region during summers 2. LÄS MER

  4. 23. Dispersion and Transformation of Traffic Exhaust Particles in the Urban Atmosphere

    Författare :Matthias Ketzel; Kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; condensation; deposition; dilution; particle size distribution; plume model; street canyon; traffic pollution; urban environment; turbulence; aerosol dynamics modelling; coagulation; Physics; Fysik; Fysicumarkivet A:2004:Ketzel;

    Sammanfattning : Ultrafine particles, their sources and fate in the atmosphere are currently key issues in atmospheric research owing to concern about their effects on human health and global climate. Traffic emissions are a dominating source of ultrafine particles, especially in urban areas. LÄS MER

  5. 24. Emissions, dynamics and dispersion of particles in polluted air

    Författare :Lars Gidhagen; Hans-Christen Hansson; Christer Johansson; Joakim Langner; Øystein Hov; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorology; Meteorologi;

    Sammanfattning : The main objective of this thesis is to yield information on how atmospheric fine and ultrafine particles are dispersed in populated areas. Quantitative information on emissions, transport and removal is needed to assess the health risks of inhalable particles. LÄS MER

  7. 25. Wet magnetic concentration for weakly magnetic mineral fines and ultrafines

    Författare :Wang Yanmin; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mineralteknik; Mineral Processing;

    Sammanfattning : The first objective of the thesis was to reveal the characteristic magnetic behaviour of natural weakly magnetic minerals (such as hematite and chromite), and the size limits of the particles recoverable by the existing modem high intensity and high gradient magnetic separators. The second objective was to enhance the particle aggregation andlor the magnetic response for wet magnetic concentration of the ultrafines which escaped from the separators. LÄS MER