Sökning: "Chemical abundance"

Visar resultat 1 - 5 av 67 uppsatser innehållade orden Chemical abundance.

  1. 1. Measuring copper abundances in the Galactic Bulge

    Kandidat-uppsats, Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Författare :Nikolei Höglinger; [2024]
    Nyckelord :Copper; Galaxy: abundances; Galaxy: bulge; Chemical Evolution; Physics and Astronomy;

    Sammanfattning : Context: The chemical evolution of Cu in the Galactic bulge have been studied in a few studies using red giant branch stars, but the ages of individual red giant stars are difficult to determine. In addition, the bulge has been a challenging region of the Milky Way galaxy to obtain high-resolution spectra of stars, except when observing through certain few small fields into the bulge that are known to have low extinction. LÄS MER

  3. 2. The quest for a classical bulge - a study of kinematics, abundances, and ages using microlensed dwarf stars and Gaia

    Master-uppsats, Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Författare :Calum Kvernes Macpherson; [2023]
    Nyckelord :Bulge; Milky Way; Kinematics; Galpy; Dwarf Stars; Physics and Astronomy;

    Sammanfattning : Context: We present an kinematical analysis of 90 F and G type dwarf, turn-off, and subgiant stars in the Galactic bulge. These stars were observed with high-resolution spectrographs during gravitational microlensing events This allowed for their ages, abundances, and radial velocities to be ascertained while they were significantly brighter. LÄS MER

  4. 3. Finding new members of the VelHel-4 stream

    Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Lucas Johansson; [2023]
    Nyckelord :Galactic Archaeology; Milky Way; Stellar Streams; Streams; Stellar Halo; Stars; Globular Cluster; Astronomy; Astrophysics; Gaia; Chemical Abundance; Spectroscopy;

    Sammanfattning : According to the paradigm of lambda-CDM cosmology, the stellar halo ofour Galaxy has been built-up over time through the accretion of other galaxiesand star clusters. The remnants of some of these are still observable today asstellar streams, but are typically very faint and difficult to resolve amidst the farmore numerous foreground Milky Way stars. LÄS MER

  5. 4. Analysis of fatty acids in fatty acid-based herbicides by gas chromatography

    Master-uppsats, Lunds universitet/Kemiska institutionen

    Författare :Mohamad Abd Elwadood; [2023]
    Nyckelord :Analytical Chemistry; Fatty Acids; Gas Chromatography; Green Herbicides; Retention Index; Flame Ionization Detector; Mass Spectrometry; Supercritical Carbon Dioxide Extraction.; Chemistry;

    Sammanfattning : Fatty acids-based herbicides are considered to be a green alternative to synthesized weed control products. However, the environmentally sustainable effect of those herbicides needs more investigation to be confirmed. LÄS MER

  7. 5. Quality of Spent Mushroom Compost Amended with Organic Material- Effect on Nutrient Content and Plant Growth

    Master-uppsats, SLU/Dept. of Biosystems and Technology (from 130101)

    Författare :Rasha Kamel; [2023]
    Nyckelord :Apple Waste; Wood Chips; Microbial Content; pH; Pseudomonas; General Bacterial Flora; General Fungal Flora; Electrical Conductivity; Nutrient Content; Bulk Density; Porosity; Water Holding Capacity;

    Sammanfattning : Peat, as a non-renewable growing media, poses environmental concerns due to extraction and decomposition processes, leading to increased greenhouse gas emissions. Alternatives growing media with potential to replace or reduce the use of peat are of great need. LÄS MER