Sökning: "carbon dust"

Visar resultat 1 - 5 av 48 avhandlingar innehållade orden carbon dust.

  1. 1. On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study

    Författare :Lars Mattsson; Susanne Höfner; Nils Bergvall; Kjell Olofsson; Martin Groenewegen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; AGB stars; carbon stars; mass loss; stellar winds; circumstellar matter; cosmic dust; stellar evolution; nucleosynthesis; galactic chemical evolution; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi; Fysik; Physics;

    Sammanfattning : Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. LÄS MER

  3. 2. A Study of Grain Drift in C Stars : Theoretical Modeling of Dust-Driven Winds in Carbon-Rich Pulsating Giant Stars

    Författare :Christer Sandin; Susanne Höfner; Bengt Gustafsson; Lee Anne Willson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; hydrodynamics; radiative transfer; instabilities; dust formation; stars: AGB and post-AGB; stars: mass-loss; stars: variables: general; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : A major fraction of stars will pass through a short period of dramatic events in their final evolutionary stage. Low- to intermediate-mass stars, studied here, are stripped of their outer parts in a slow massive wind. This mass loss reshapes both the star and the surrounding medium. LÄS MER

  4. 3. Occupational air pollutants and non-malignant respiratory disorders especially in miners

    Författare :Ulf Hedlund; Per Gustavsson; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; respiratory symptoms; occupational epidemiology; mining; asthma; airway inflammation; dust; diesel exhaust; quartz; chronic bronchitis; silicosis; Occupational and Environmental Medicine; arbets- och miljömedicin;

    Sammanfattning : Aim. To assess associations between occupational air pollution and respiratory health, especially in miners.Background. Indications of associations between occupational exposure or social economic status and respiratory health have been found in several population-based studies. LÄS MER

  5. 4. Modelling optical properties of morphologically complex aerosols

    Författare :Franz Kanngiesser; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; remote sensing; sea salt; black carbon; aerosol; scattering; mineral dust.; depolarisation;

    Sammanfattning : The interpretation of remote sensing data of atmospheric aerosol particles requires a thorough understanding of the links between microphysical and optical properties. Morphologically complex aerosol models describe the particles’ morphology in detail. LÄS MER

  7. 5. Urban Climate and Air Pollution in Ouagadougou, Burkina Faso

    Författare :Jenny Lindén; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sub-Saharan Africa; Sahel; semi arid; nocturnal cooling; urban vegetation; evening evaporative cooling; cooling rate; atmospheric stability; thermal wind; carbon monoxide; particulate matter; road dust; exposure differences;

    Sammanfattning : ABSTRACT Africa has recently been singled out by UN Habitat as the fastest urbanizing continent in the world. The most extreme case was found in the Sahelian city of Ouagadougou, Burkina Faso, where the population is expected to almost double over the next ten years. LÄS MER