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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Micro texturing of surfaces for improved tribological properties

   Författare :U Pettersson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Teknisk materialvetenskap;

   Sammanfattning : .... LÄS MER

3. 2. Mesoproterozoic crustal evolution in Southern Africa

   Författare :Åsa Pettersson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Namaqua-Natal province; Mezoproterozoic; geochronology; U-Pb zirkon dating; Sm-Nd model ages; Ar-Ar dating; Southern Africa;

   Sammanfattning : The objects of this thesis were to use geochronology to investigate crustal evolution of part of Southern Africa that formed during a global event, resulting in the ~1 Ga supercontinent Rodinia. The timing of assembly by continent-continent collisions and the position of the individual continental blocks of this ancient landmass is still largely unknown. LÄS MER

4. 3. Tectonic evolution of NW Svalbard

   Författare :Carl Pettersson; Stockholms universitet; []
   Nyckelord :Svalbard; Migmatization; Zircon; Provenance;

   Sammanfattning : The Neoproterozoic is a remarkable era in Earth’s history with dramatic variations in climate and biota, possibly resulting in global glaciations events (eg. “snowball earth”, Kirschvink, 1992) and the first appearance of metazoans (Conway Morris, 1993). LÄS MER

5. 4. Accuracy of virtually planned and CAD/CAM-guided dental implant surgery

   Författare :Andreas Pettersson; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :dental implant;

   Sammanfattning : The treatment with dental implants was introduced in the 1960s as an aid for patients who were missing teeth. Recently CAD/CAM guided surgical concepts have been launched on the market as a solution for treating single, partial or completely edentulous patients with dental implants. LÄS MER

7. 5. The tectonic evolution of northwest Svalbard

   Författare :Carl Henrik Pettersson; Victoria Pease; Robert Strachan; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Svalbard; Rodinia; Laurentia; Zircon; Provenance; Migmatites; Clockwise P-T; Solid earth geology and petrology; Berggrundsgeologi och petrologi; Geology; geologi;

   Sammanfattning : Svalbard represents the uplifted and exhumed northwest corner of the Barents Sea Shelf. Pre-Carboniferous rocks of Svalbard are divided into the Eastern, Northwestern and Southwestern Terranes, were amalgamated during the Caledonian Orogen and are separated by north-south-trending strike-slip faults. LÄS MER