Sökning: "high temperatures"
Visar resultat 1 - 5 av 1617 avhandlingar innehållade orden high temperatures.
1. Experimental Study of some Potassium and Sodium Bearing Aluminosilicates at High Temperatures and High Pressures
Sammanfattning : 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. LÄS MER
2. Mössbauer spectroscopy under high pressures and temperatures
Sammanfattning : 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. LÄS MER
3. High temperature galling : influencing parameters and mechanisms
Sammanfattning : 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. LÄS MER
4. High-Efficiency SiC Power Conversion : Base Drivers for Bipolar Junction Transistors and Performance Impacts on Series-Resonant Converters
Sammanfattning : 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. LÄS MER
5. Some calorimetric measurements at high temperatures : determination of Thomson coefficients : measurements of evolution of heat during precipitation and order-disorder transitions in alloys
Sammanfattning : .... LÄS MER