Sökning: "two-dimensional solutions"

Visar resultat 21 - 25 av 98 avhandlingar innehållade orden two-dimensional solutions.

1. 21. Black-Hole Universe

   Författare :Irina Galstyan; Kjell Rosquist; Ingemar Bengtsson; Sören Holst; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical Physics; teoretisk fysik;

   Sammanfattning : In this thesis, we have constructed new analytical solutions for initial data of the Einstein equations. Such solutions are valuable for gaining a better understanding of problems involving strong gravitational and/or electromagnetic interactions in general relativity. LÄS MER

3. 22. Thermomechanical Modelling of Tribological Systems

   Författare :Niclas Strömberg; Alain Curnier; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The present thesis concerns the thermomechanical modelling of contact, friction and wear. Within a framework of continuum thermodynamics, Signorini's contact conditions, Coulomb's law of friction and Archard's law of wear are derived by means of a free energy and a dissipation potential. LÄS MER

4. 23. Modeling and optimization of least-cost corridors

   Författare :Lindsi Seegmiller; Takeshi Shirabe; Kai-Florian Richter; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; raster data modeling; raster-based geographic information systems; route planning; optimal routing; corridor; wide path; corridor width; distortion; three-dimensional grid; rasterdatamodellering; rasterbaserade geografiska informationssystem; ruttplanering; optimal dirigering; korridor; bred väg; korridorbredd; distorsion; tredimensionellt rutnät; Geoinformatics; Geoinformatik;

   Sammanfattning : Given a grid of cells, each having a value indicating its cost per unit area, a variant of the least-cost path problem is to find a corridor of a specified width connecting two termini such that its cost-weighted area is minimized. A computationally efficient method exists for finding such corridors, but as is the case with conventional raster-based least-cost paths, their incremental orientations are limited to a fixed number of (typically eight orthogonal and diagonal) directions, and therefore, regardless of the grid resolution, they tend to deviate from those conceivable on the Euclidean plane. LÄS MER

5. 24. Painlevé analysis and transformations for nonlinear partial differential equations

   Författare :Ove Lindblom; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Sammanfattning : Nonlinear partial differential equations play a fundamental role in the description of many physical models. In order to get a complete understanding of the phenomena which are modeled it is important to obtain exact analytic solutions. LÄS MER

7. 25. New Fullerene Materials Obtained in Solution and by High Pressure High Temperature Treatment

   Författare :Alexandr Talyzin; B. Sundqvist; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; fullerene; solution; high pressure; Raman spectroscopy; polymerisation; XRD; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Crystallization of C60 and C70 from organic solution often leads to the formation of new solvates and other fullerene compounds. In the present thesis, a number of such solvates were obtained and their phase transitions studied using in situ "in solution" techniques. LÄS MER