Sökning: "high-pressure physics"
Visar resultat 11 - 15 av 67 avhandlingar innehållade orden high-pressure physics.
11. Physical Properties and Structural stability of carbon nanotubes under extreme conditions
Sammanfattning : Carbon nanotubes (CNTs) have attracted an immense attention of the research community since reporting on this system by S. Ijima in 1991. A "single-walled" CNT (SWCNT) can be considered as a rolled-up single-layer graphene - a one atom-thick layer of carbon atoms arranged in a hexagonal lattice. LÄS MER
12. Studies of carbon nanomaterials based on fullerenes and carbon nanotubes
Sammanfattning : Materials based on fullerenes and carbon nanotubes are very much different from most “traditional” materials, primarily because they are built from nanosized molecules with highly symmetry-dependent properties. Being the subject of a very active research field over the last twenty years, carbon nanostructures proved to be indeed extraordinary. LÄS MER
13. Understanding Physical Reality via Virtual Experiments
Sammanfattning : In this thesis I have studied some problems of condensed matter at high pressures and temperatures by means of numerical simulations based on Density Functional Theory (DFT).The stability of MgCO3 and CaCO3 carbonates at the Earth's mantle conditions may play an important role in the global carbon cycle through the subduction of the oceanic crust. LÄS MER
14. On the Use of Laser-Induced Incandescence for Soot Diagnostics: From Theoretical Aspects to Applications in Engines
Sammanfattning : The laser-induced incandescence technique (LII) is a laser-based diagnostic technique for measurements of soot volume fraction and particle size. The technique relies on detection of incandescent light from soot particles heated to around 4000 K using nanosecond laser pulses. LÄS MER
15. Atomistic Computer Simulations of the Melting Process and High Pressure Conditions
Sammanfattning : 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. LÄS MER
