Sökning: "Rare earth elements"
Visar resultat 16 - 20 av 75 avhandlingar innehållade orden Rare earth elements.
16. Assessing the reliability of detrital zircon in Early-Earth provenance studies
Sammanfattning : Our understanding of the Early Earth and the processes that have shaped its evolution have spawned predominantly from the geochemical and isotopic signatures of a small number of zircon populations around the world. Studies of trace element distributions, Hf and O isotope systematics as well as mineral inclusion chemistry in detrital zircon are combined with U-Pb chronology in order to constrain source rock characteristics. LÄS MER
17. Hybrid nanoadsorbents for extraction and separation of rare earth elements in solution
Sammanfattning : Rare Earth Elements (REE) are a group of 17 metals (those known as lanthanides plus Ytrium and Scandium), which are increasingly important for many emerging modern applications. This work is focused on the development of high performance new magnetic silica based nanoadsorbents which are surface functionalized for efficient uptake and separation of REE in solution. LÄS MER
18. Light-Matter Interaction and Quantum Computing in Rare-Earth-Ion-Doped Crystals
Sammanfattning : In this thesis, crystals of yttrium orthosilicate (Y2SiO5) that are randomly doped with another rare-earth element, such as praseodymium (Pr), europium (Eu), or cerium (Ce), are investigated with lasers locked to ultra-stable cavities using the Pound-Drever-Hall locking technique. Many of these rare-earth elements have long-lived 4f-4f transitions, hundreds of microseconds to a few milliseconds, with even longer ground hyperfine lifetimes of up to several days. LÄS MER
19. Speciation and fractionation of Ca and the REE in fresh and marine waters
Sammanfattning : This study is concerned with speciation and fractionation of the rare earth elements (REE) and calcium (Ca) in aqueous solutions. The aim is to investigate the chemical states and physical sizes in which these elements can be present. The REE (including neodymium) and Ca have contrasting geochemical behavior in aqueous solutions. LÄS MER
20. Structure-Magnetism Relations in Selected Iron-based Alloys : A New Base for Rare Earth Free Magnetic Materials
Sammanfattning : Materials for energy applications are of great importance for a sustainable future society. Among these, stronger, lighter and more efficient magnetic materials will be able to aid mankind in many applications for energy conversion, for example generators for energy production, electric vehicles and magnetic refrigerators. LÄS MER
