Sökning: "Oscillatory Instabilities"

Hittade 4 avhandlingar innehållade orden Oscillatory Instabilities.

  1. 1. Waves and instabilities in quantum plasmas

    Författare :Shahid Ali; Padma Kant Shukla; Mattias Marklund; Jose Tito Mendonca; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum mechanical effects; dusty plasma; linear and nonlinear waves; instabilities; nonlinear wave interactions; density gradients; magnetoplasmas.; Plasma physics; Plasmafysik;

    Sammanfattning : The study of waves and instabilities in quantum plasmas is of fundamental importance for understanding collective interactions in superdense astrophysical objects, in high intense laser-plasma/solid-matter interactions, in microelectronic devices and metallic nanostructures. In dense quantum plasmas, there are new pressure laws associated with the Fermi-Dirac distribution functions and new quantum forces associated with the quantum Bohm potential and the Bohr magnetization involving electron ½ spin. LÄS MER

  3. 2. Comparisons between classical and quantum mechanical nonlinear lattice models

    Författare :Peter Jason; Magnus Johansson; Jonas Larson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Discrete Breathers; Bose-Einstein-Condensation; Instabilities; Oscillatory Instabilities; Classical-Quantum correspondence; Bose-Hubbard model; DNLS; discrete nonlinear Schrödinger equation; nonlinear; nonlinear lattice models; compacton;

    Sammanfattning : In the mid-1920s, the great Albert Einstein proposed that at extremely low temperatures, a gas of bosonic particles will enter a new phase where a large fraction of them occupy the same quantum state. This state would bring many of the peculiar features of quantum mechanics, previously reserved for small samples consisting only of a few atoms or molecules, up to a macroscopic scale. LÄS MER

  4. 3. Generation of magnetic fields in plasmas

    Författare :Nitin Shukla; Gert Brodin; Dusan Jovanovic; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Relativistic and non-relativistic plasma outflows are quite ubiquitous in astrophysical scenarios, as well as in laboratory plasmas. The propagation of relativistic and non- relativistic charged particle beams in background plasmas provides return currents in the opposite direction and interactions between the currents then drive several plasma instabilities involving the longitudinal (electrostatic instabilities) and trans- verse (electromagnetic instability) modes. LÄS MER

  5. 4. Opportunities and challenges of surface scattering at next generation neutron sources

    Författare :Franz Alois Adlmann; Henrich Frielinghaus; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GISANS; data reduction; off-specular; neutron scattering; reflectometry; complex fluids; rheology;

    Sammanfattning : Complex fluids and soft matter are ubiquitously found in the world and all contacts in life are made over surfaces. To describe the mechanical behavior of such substances, rheological methods are used. Flow instabilities are a big challenge in rheology since they will be reflected in the macroscopic variables probed, like e. g. LÄS MER