Search for dissertations about: "Earths inner core"

Showing result 1 - 5 of 7 swedish dissertations containing the words Earths inner core.

  1. 1. Effects of disorder in metallic systems from First-Principles calculations

    Author : Christian Asker; Igor Abrikosov; Jörg Neugebauer; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Iron; Nickel; Magnesium; Manganese; Molybdenum; Zirconium; Elastic Constants; High pressure; Earth s core; Density-functional theory; Ab-initio; First-Principles; Core-level shifts; Molecular Dynamics; Phonons; Dynamical Instability; Condensed matter physics; Kondenserade materiens fysik; Computational physics; Beräkningsfysik;

    Abstract : In this thesis, quantum-mechanical calculations within density-functional theory on metallic systems are presented. The overarching goal has been to investigate effects of disorder. In particular, one of the properties investigated is the bindingenergy shifts for core electrons in binary alloys using different theoretical methods. READ MORE

  2. 2. Atomistic Computer Simulations of the Melting Process and High Pressure Conditions

    Author : Sergio Davis; Börje Johansson; Mikhail Dzugutov; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material physics with surface physics; Materialfysik med ytfysik;

    Abstract : The present work describes the use of atomistic computer simulations in the area of Condensed Matter Physics, and specifically its application to the study of two problems: the dynamics of the melting phase transition and the properties of materials at extreme high pressures and temperatures, problems which defy experimental measurements and purely analytical calculations. Both classical Molecular Dynamics (using semi–empirical interaction potentials) and first–principles (ab initio) Molecular Dynamics techniques has been applied in this study to the calculation of melting curves in a wide range of pressures for elements such as Xe and H2, the study of the elastic constants of Fe at the conditions of the Earth’s inner core, and the characterization of diffusion and defects formation in a generic Lennard–Jones crystal at the limit of superheating, including the role they play in the triggering of the melting process itself. READ MORE

  3. 3. Atomistic Computer Simulations of Melting, Diffusion and Thermal Defects in High Pressure Solids

    Author : Sergio Davis; Anatoly Belonoshko; Börje Johansson; Leonid Zhigilei; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Teknisk materialvetenskap;

    Abstract : The present work describes the use of atomistic computer simulations in the area of Condensed Matter Physics, and speci cally its application to the study of two problems: the dynamics of the melting phase transition and the properties of materials at extremely high pressures and temperatures, problems which defy experimental measurements and purely analytical calculations. A good sampling of techniques including classical and rst-principles Molecular Dynamics, and Metropolis Monte Carlo simulation have been applied in this study. READ MORE

  4. 4. Influence of stresses and impurities on thermodynamic and elastic properties of metals and alloys from ab initio theory

    Author : Olga Vekilova; Igor Abrikosov; Sergei Simak; Björn Winkler; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Stresses and impurities may influence elastic properties, phase stability and magnetic behavior of metals and their alloys. A physical understanding of this influence is of great importance to both fundamental science and technological applications. READ MORE

  5. 5. Implementation of the spectral element method and iterative solution techniques for 3D controlled-source electromagnetic modelling

    Author : Michael Weiss; Thomas Kalscheuer; Michael Becken; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Controlled source electromagnetis; Electromagnetic theory; Numerical modelling; Applied geophysics; Geo-Electromagnetics; Spectral element method; Iterative solution methods; Preconditioning;

    Abstract : Controlled-source electromagnetic methods are imaging techniques applied at/on the surface of the Earth which record the electromagnetic field in order to assess the electrical conductivity distribution of the Earth’s subsurface, along with anomalies in this material property, as well as to characterise and interpret structures in Earth’s crust. Extracting information from the recorded electromagnetic data requires inverse modelling algorithms. READ MORE