Essays about: "Chemical Evolution"

Showing result 1 - 5 of 61 essays containing the words Chemical Evolution.

  1. 1. Measuring copper abundances in the Galactic Bulge

    University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

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

    Abstract : 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. READ MORE

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

    University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

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

    Abstract : 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. READ MORE

  4. 3. The chemical evolution of the Milky Way: pushing APOGEE to higher precision and accuracy

    University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Author : Erik Fridén; [2023]
    Keywords : Physics and Astronomy;

    Abstract : In the recent decade, a rapid increase in all-sky spectroscopic surveys has occurred, and with it, the wealth of observational data and information on our Galaxy. Consequently, numerous detections of new structures, such as new open clusters, accreted and in-situ components, are discovered. READ MORE

  5. 4. Flight Dynamics Software Industrialisation for Inclined Orbits

    University essay from KTH/Lättkonstruktioner, marina system, flyg- och rymdteknik, rörelsemekanik

    Author : Pierrick Houede; [2023]
    Keywords : flight; dynamics; software; FDS; geostationary; orbit; station; keeping; uncontrolled; inclination.;

    Abstract : The geostationary orbit has many applications for Earth observation and telecommunications. Like all satellites, spacecraft in this type of orbit are affected by perturbations. These perturbations can modify the satellites trajectories and, without control, deviate them from their target position. READ MORE

  6. 5. Experimental studies of radiation damage in uranium nitride

    University essay from KTH/Fysik

    Author : Maria Giamouridou; [2023]
    Keywords : uranium nitride nuclear fuel; advanced nuclear fuel; uranium nitride fabrication; uranium nitride characterisation; Spark Plasma Sintering; proton irradiation; irradiation damage; TANDEM accelerator; irradiation induced cracking; irradiation induced hardening; irradiation induced swelling; hydrogen implantation; dislocation loops; kärnbränsle av urannitrid; avancerat kärnbränsle; tillverkning av urannitrid; karakterisering av urannitrid; Spark Plasma Sintering; protonbestrålning; strålningsskador; TANDEM-accelerator; strålningsinducerad sprickbildning; strålningsinducerad härdning; strålningsinducerad svällning; väteimplantation; dislokationsloopar;

    Abstract : The effect of proton (H+) irradiation on uranium mononitride (UN) and UN compositefuel with 10 at.% ZrN (UN10at%ZrN) was examined. Protons of 2 MeV with fluences of1E17, 1E18, 1E19 and 1E20 ions/cm2 were accelerated towards the fabricated samples in orderto investigate the evolution of the micro-structure. READ MORE