Search for dissertations about: "coherent structures"

Showing result 1 - 5 of 136 swedish dissertations containing the words coherent structures.

  2. 1. Coherent structures and control in wall-bounded turbulent flows

    Author : Marco Atzori; Philipp Schlatter; Ricardo Vinuesa; Oscar Flores; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent boundary layers; numerical simulations; coherent structures; predetermined flow control.; Turbulenta gränsskikt; numeriska simuleringar; koherenta strukturer; förutbestämd flödeskontroll; Teknisk mekanik; Engineering Mechanics;

    Abstract : This thesis is concerned with two distinct topics related to the study of wall-bounded turbulence: the connection between instantaneous three-dimensional coherent structures and mean-flow properties, and the development and analysis of pre-determined control techniques for adverse-pressure-gradient boundary layers.We examined regions with intense velocity fluctuations in various flowcases. READ MORE

  4. 2. Space Plasma Dynamics : Instabilities, Coherent Vortices and Covariant Parametrization

    Author : David Sundkvist; Jan-Erik Wahlund; Andris Vaivads; Stuart Bale; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma; instabilities; turbulence; coherent structures; vortex; self-organization; magnetosphere; waves; electromagnetism; covariant; space instrumentation; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Abstract : The magnetospheric cusps are two funnel-like regions of Earth's magnetosphere where solar wind plasma can have direct access to the ionosphere. The cusps are very dynamic regions where wave-particle interactions continuously take place and redistribute energy among different particle populations. READ MORE

  5. 3. On Coherent and Non-coherent Receiver Structures for Impulse Radio UWB Systems

    Author : Muhammad Gufran Khan; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The demand and growth of short-range wireless communications has been tremendous in the past few years for a diverse range of applications. There is significant interest in ultra wideband (UWB) as a physical layer technology for both high-data-rate (HDR), and low power, low-data-rate (LDR) short-range communications. READ MORE

  6. 4. Ultrafast Coherent X-ray Diffractive Nanoimaging

    Author : Filipe R. N. C. Maia; Janos Hajdu; David van der Spoel; Keith Nugent; Uppsala universitet; []
    Keywords : XFEL; Phasing; Image Reconstruction; Single Particle Imaging; Ultrafast Diffraction; X-ray diffraction; Coherent Diffractive Imaging; CXDI;

    Abstract : X-ray lasers are creating unprecedented research opportunities in physics,chemistry and biology. The peak brightness of these lasers exceeds presentsynchrotrons by 1010, the coherence degeneracy parameters exceedsynchrotrons by 109, and the time resolution is 105 times better. READ MORE

  7. 5. Coherent Diffractive Imaging with X-ray Lasers

    Author : Max Felix Hantke; Filipe R. N. C. Maia; Janos Hajdu; Martin Svenda; Edgar Weckert; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; coherent diffractive X-ray imaging; lensless imaging; coherent X-ray diffractive imaging; flash diffractive imaging; single particle imaging; aerosol injection; electrospray injection; substrate-free sample delivery; carboxysome; phase retrieval; X-ray diffraction software; X-ray free-electron laser; XFEL; FEL; CXI; CDI; CXDI; FXI;

    Abstract : The newly emerging technology of X-ray free-electron lasers (XFELs) has the potential to revolutionise molecular imaging. XFELs generate very intense X-ray pulses and predictions suggest that they may be used for structure determination to atomic resolution even for single molecules. READ MORE