Sökning: "LA ICP-MS"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden LA ICP-MS.

1. 1. Re-Os dating of molybdenite : new anlytical approaches using ICP-MS

   Författare :Dmitry Malinovskiy; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Sammanfattning : In recent years, there has been a surge of interest in the direct dating of ore deposits using Re-Os geochronometer for the ore minerals themselves. Molybdenite has been or particular interest because it is a common ore mineral and is suitable for analysis by the Re-Os method due to relatively high concentration of both Re and Os. LÄS MER

3. 2. Multi-element analysis of environmental samples using LA-ICP-MS : method developments with emphasis on calibration strategies

   Författare :Mikael D. Axelsson; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Sammanfattning : Analytical applications based on the use of laser ablation-inductively coupled plasma-sector field mass spectrometry (LA-ICP-SFMS) have shown great potential for both quantitative and qualitative determination of elements in a variety of materials, although the weak point is finding a suitable calibration approach. The major focus of this work has, therefore, been internal standardisation and calibration. LÄS MER

4. 3. Interconnections : Glass beads and trade in southern and eastern Africa and the Indian Ocean - 7th to 16th centuries AD

   Författare :Marilee Wood; Paul Sinclair; Anneli Ekblom; Paul Lane; Uppsala universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; glass trade beads; glass analysis; LA-ICP-MS; 7th to 16th century Indian Ocean trade; southern Africa; East Africa; Mapungubwe; K2; Schroda; Chibuene; Hlamba Mlonga; Sibudu Cave; Kaole Ruins; Mahilaka.; Arkeologi; Archaeology;

   Sammanfattning : Glass beads comprise the most frequently found evidence of trade between southern Africa and the greater Indian Oceanbetween the 7th and 16th centuries AD.  In this thesis beads recovered from southern African archaeological sites are organized into series, based on morphology and chemical composition determined by LA-ICP-MS analysis. LÄS MER

5. 4. Chloride Induced Corrosion of Reinforcement Steel in Concrete - Threshold Values and Ion Distributions at the Concrete-Steel Interface

   Författare :Nelson Dias Ferreira Da Silva; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LA-ICP-MS; pitting corrosion; chloride threshold values; concrete-steel interface;

   Sammanfattning : The chloride threshold value (Cth), or critical chloride content, is defined as the chloride concentration at the depth of the reinforcement, which initiates the depassivation of steel in concrete. However, very limited information is available regarding the chloride distributions at the interface with the steel. LÄS MER

7. 5. Crystallization and Differentiation Processes in the Thin Layered Alkali Gabbroic Intrusions of the Ulvö Gabbro Complex, Central Sweden

   Författare :Johan Hogmalm; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; layered intrusion; fractional crystallization; modal layering; in situ crystallization; Ulvö; saucer-shaped sill; post-cumulus; LA ICP-MS;

   Sammanfattning : Fractional crystallization of magma is a commonly invoked mechanism for chemical differentiation in systems that range from volcanoes to entire planets. However, the processes that control separation of crystals and liquids in natural systems remain controversial, since the dynamics of crystallizing magma chambers cannot be studied directly. LÄS MER