Sökning: "Rare earth elements"

Visar resultat 26 - 30 av 75 avhandlingar innehållade orden Rare earth elements.

  1. 26. New and old materials for permanent magnets based on earth-abundant elements

    Författare :Daniel Hedlund; Peter Svedlindh; Martin Sahlberg; Mogens Christensen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; permanent magnets; material development; sustainability; Engineering Science with specialization in Solid State Physics; Teknisk fysik med inriktning mot fasta tillståndets fysik;

    Sammanfattning : Electrical motors, which find use in e.g. electrical vehicles, require per-manent magnets to function. Comparing ferrite magnets and Nd-based magnets reveals a large difference in their price and performance. LÄS MER

  2. 27. Unlocking the hidden diversity of organic-walled microfossils from the early Cambrian of North Greenland

    Författare :Elise Wallet; Sebastian Willman; Ben Slater; Graham Budd; Charles H. Wellman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cambrian; acritarchs; organic-walled microfossils; small carbonaceous fossils; Greenland; diversity; disparity; taxonomy; taphonomy; Crustacea; plankton; Historical Geology and Paleontology; Historisk geologi och paleontologi;

    Sammanfattning : The early Cambrian Buen Formation of North Greenland is celebrated for hosting one of the oldest Cambrian Burgess Shale-type deposits known to date – the Sirius Passet Lagerstätte. Further south in a shallower shelf facies belt, the Buen Formation yielded organic-walled microfossils (OWMs) that were originally described with a focus on acritarchs. LÄS MER

  3. 28. Magma generation and formation of continental crust in the Izu arc

    Författare :Haochen Duan; Abigail Barker; Jaroslaw Majka; Stefan Wastegård; Kate Saunders; Susanne M. Straub; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Oceanic arc; Izu rear-arc; Melt inlcusions; Oxygen isotopes; Boron isotopes; Continental crust; Mantle hererogeneity; In-situ microanalysis; IMS-1280; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : The Izu oceanic arc is produced by the subduction of the Pacific Sea Plate beneath the Philippine Sea Plate. The proto-Izu oceanic arc was initially formed at ca. 50 Ma, then it was separated into the Kyushu-Palau and Izu arc by the extension of the Shikoku basin from ca. 25 Ma. LÄS MER

  4. 29. Experimental and Computational Magnetic Resonance Studies of Selected Rare Earth and Bismuth Complexes

    Författare :Vasantha Gowda; Oleg Antzutkin; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Chemistry of Interfaces; Gränsytors kemi;

    Sammanfattning : The rare-earth elements (REEs) and bismuth, being classified as the ‘most critical raw materials’ (European Raw Materials Initiatives, 2017), have a high economic importance to the EU combined with a high relative supply risk. REEs are highly important for the evolving technologies such as clean-energy applications, high-technology components, rechargeable batteries, permanent magnets, electric and hybrid vehicles, and phosphors monitors. LÄS MER

  5. 30. Structure of Rare-Earth Aluminosilicate Glasses Probed by Solid-State NMR Spectroscopy and Quantum Chemical Calculations

    Författare :Aleksander Jaworski; Mattias Edén; Thibault Charpentier; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysikalisk kemi; Physical Chemistry;

    Sammanfattning : Aluminosilicate glasses incorporating rare earth elements feature highly beneficial physical and chemical properties, at the level beyond that accessible for compositions based on alkali and/or alkaline earth metals. Extraordinary hardness, high glass transition temperatures and indices of refraction, favorable coefficients of thermal expansion, as well as excellent chemical durability, result in many potential technological applications. LÄS MER