Search for dissertations about: "metallicity"

Showing result 16 - 20 of 25 swedish dissertations containing the word metallicity.

  2. 16. Ca-Pd/Pt-Ge Compounds on the Zintl Border

    Author : Isa Doverbratt; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Zintl compounds form a category in intermetallic chemistry somewhere between metallic and ionic compounds. Classical Zintl compounds form between electropositive and electronegative elements, such as the alkaline earth metals and the p-block elements, i.e. elements with a relatively large electronegativity difference. READ MORE

  4. 17. Galactic archaeology with metal-poor stars

    Author : Thomas Nordlander; Andreas J. Korn; Karin Lind; Ulrike Heiter; David L. Lambert; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: abundances; radiative transfer; stars: Population II; stars: Population III;

    Abstract : The chemical fingerprints of old, metal-poor stars can be used to unravel the events of the newborn Universe and help us understand the properties of the first stars and star clusters. The study of nearby stars to infer properties in the distant past is often referred to as Galactic archaeology. READ MORE

  5. 18. Observational Studies of the Chemical Evolution in the Galactic Thin and Thick Disks

    Author : Thomas Bensby; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Astronomi; Fysicumarkivet A:2004:Bensby;

    Abstract : The origin and evolution of the thin and thick disks in the Galaxy have been studied by means of detailed stellar abundances. High-resolution spectra of 102 F and G dwarf stars have been obtained with the spectrographs on the ESO 3.6-m and ESO 1. READ MORE

  6. 19. Core-collapse Supernovae : Theory vs. Observations

    Author : Dennis Alp; Josefin Larsson; Sergey Tsygankov; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astrophysics; Supernovae; Fysik; Physics;

    Abstract : A core-collapse supernova (CCSN) is an astronomical explosion that indicates the death of a massive star. The iron core of the star collapses into either a neutron star or a black hole while the rest of the material is expelled at high velocities. READ MORE

  7. 20. Atomic Processes in Stellar Atmospheres : Inelastic Collisions and Effects on Late-type Spectra

    Author : Yeisson Fabian Martinez Osorio; Paul Barklem; Karin Lind; Nikolai Piskunov; Carlos Allende Prieto; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Spectral line: formation; atomic data; stellar abundances.; Fysik med inriktning mot astrofysik; Physics with specialization in Astrophysics;

    Abstract : Chemical abundances as measured from stellar spectral lines are often subject to uncertainties due to lack of accurate data for inelastic collisions, which is needed for non-local thermodynamic equilibrium (non-LTE) modelling. For cool stars, understanding of collision processes with electrons and hydrogen atoms is required to achieve high precision measurements. READ MORE