Search for dissertations about: "High temperatures"

Showing result 1 - 5 of 1617 swedish dissertations containing the words High temperatures.

  2. 1. Experimental Study of some Potassium and Sodium Bearing Aluminosilicates at High Temperatures and High Pressures

    Author : Faramarz Tutti; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Phlogopite; Orthoclase; Jadeite; Albite; Calcium ferrite; Hollandite; Dehydroxylation; High temperature; High pressure; Lower mantle; Geochemistry; Geovetenskap; Earth sciences; Geovetenskap; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

    Abstract : This dissertation presents the results of a high-temperature and high-pressure experimental study of some abundant aluminositicates, which are the main repositories for the two geochemically important elements, sodium and potassium, in the Earth's crust. Phase transitions of end member alkali feldspars and jadeite clinopyroxene are studied at high and ultrahigh pressures corresponding to the conditions between the transition zone and the deep Earth's lower mantle. READ MORE

  4. 2. Mössbauer spectroscopy under high pressures and temperatures

    Author : Elke Hålenius; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Mössbauer; high pressure - high temperature; iron; olivine; Geovetenskap; Earth sciences; Geovetenskap; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

    Abstract : Iron plays a very important role in Earth materials. 57Fe- Mössbauer spectroscopy provides valuable information on the oxidation state and the near surrounding of iron atoms in crystal structures. READ MORE

  5. 3. High temperature galling : influencing parameters and mechanisms

    Author : Leonardo Pelcastre; Jens Bergström; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements; Centrumbildning - Centrum för högpresterande stål CHS ; Centre - Centre for High Performance Steel CHS ;

    Abstract : Damage of forming tools at elevated temperatures is a major problem in metal forming processes such as hot stamping. Of special importance is the occurrence of adhesion and gross material transfer from the work-piece to the tool surface, a phenomenon known as galling. READ MORE

  6. 4. High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters

    Author : Georg Tolstoy; Hans-Peter Nee; Stig Munk-Nielsen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon Carbide; Bipolar Junction Transistor BJT ; Resonant converter; Series-resonant converter SLR ; Base drive circuits; High- Efficiency Converters; High-Frequency Converters; Electrical Engineering; Elektro- och systemteknik;

    Abstract : This thesis aims to bring an understanding to the silicon carbide (SiC) bipolar junction transistor (BJT). SiC power devices are superior to the silicon IGBT in several ways. They are for instance, able to operate with higher efficiency, at higher frequencies, and at higher junction temperatures. READ MORE

  7. 5. Some calorimetric measurements at high temperatures : determination of Thomson coefficients : measurements of evolution of heat during precipitation and order-disorder transitions in alloys

    Author : Josef Nyström; Stockholms högskola; []
    Keywords : ;

    Abstract : .... READ MORE