Sökning: "Atmospheric physics"

Visar resultat 11 - 15 av 135 avhandlingar innehållade orden Atmospheric physics.

  1. 11. Hygroscopic Properties of Aerosols from Open-Air Burning and Controlled Combustion of Biomass

    Författare :Jenny Rissler; Kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cloud condensation nuclei; H-TDMA; CCN; hygroscopic growth; Teknik; internal and external mixture; CLAIRE; SMOCC; Physics; Fysik; Environmental chemistry; Technological sciences; Miljökemi; tandem differential mobility analyzer; slash and burn; Amazon; Biomass burning; combustion; Fysicumarkivet A:2005:Rissler;

    Sammanfattning : The major uncertainty in predicting the influence of human activities on global climate change is the effect of aerosols. Two physical properties of aerosols largely controlling their influence on climate are the particle number size distribution and the interaction of the particles with the surrounding water vapor. LÄS MER

  3. 12. Physicochemical properties and atmospheric ageing of soot - investigated though aerosol mass spectrometry

    Författare :Axel Eriksson; Kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Black carbon; soot; vehicle exhausts; wood stove emissions; atmospheric processing; SP-AMS;

    Sammanfattning : Aerosol particles contribute significantly to the global burden of disease, and remain the main source of uncertainty in assessments of human-induced climate change. The microphysical characterization of particles is necessary to understand the roles they play in the detrimental effects of air pollution on human health, and in the energy budget of our planet. LÄS MER

  4. 13. The effect of surface steps and oxides on the catalytic activity on model Pd and Rh catalysts

    Författare :Chu Zhang; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Surface X-ray diffraction SXRD ; X-ray photonelectron spectroscopy; Catalytic activity; Oxide; Single Crystal surface; surface structure; vicinal surface; CO oxidation; stepped surface; Fysicumarkivet A:2018:Zhang;

    Sammanfattning : A catalyst is a substance that can speed up the rate of a chemical reaction without itself being consumed. Catalysts are crucial for chemical production industries, where about 90% of all chemicals are produced using catalysts. LÄS MER

  5. 14. On the Use of Laser-Induced Incandescence for Soot Diagnostics: From Theoretical Aspects to Applications in Engines

    Författare :Henrik Bladh; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Laser-Induced Incandescence; Laser Diagnostics; LII; Soot; Model; Engine; Particulates; Soot volume fraction; Combustion; Physics; Fysik; quantum mechanics; classical mechanics; Mathematical and general theoretical physics; Matematisk och allmän teoretisk fysik; thermodynamics; statistical physics; gravitation; relativity; kvantmekanik; klassisk mekanik; termodynamik; statistisk fysik; relativitet; Gases; Gaser; fluid dynamics; plasmas; Teknik; Laserteknik; Motors and propulsion systems; Motorer; framdrivningssystem; fluiddynamik; plasma; Technological sciences; Laser technology;

    Sammanfattning : The laser-induced incandescence technique (LII) is a laser-based diagnostic technique for measurements of soot volume fraction and particle size. The technique relies on detection of incandescent light from soot particles heated to around 4000 K using nanosecond laser pulses. LÄS MER

  7. 15. Escape to space or return to venus : ion flows measured by venus express

    Författare :Moa Persson; Yoshifumi Futaana; Hans Nilsson; Maria Hamrin; Dmitrij Titov; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Venus; water; escape; planetary physics; oxygen; O ; hydrogen; H ; ions; space physics; space plasma physics; Venus Express; ASPERA-4; IMA; spacecraft measurements; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : The present-day Venusian atmosphere is crushingly dense, extremely hot and arid. Yet, in its early history, Venus presumably had a massive amount of water, which, if spread evenly over the surface, provided a water depth of 10s to 100s of meters. Therefore, over the course of the atmospheric evolution, the water must have been removed from Venus. LÄS MER