Sökning: "Fast dynamics"

Visar resultat 1 - 5 av 385 avhandlingar innehållade orden Fast dynamics.

  1. 1. Ultrafast Magnetization Dynamics : Element-selective studies of magnetic alloys using ultra short XUV pulses

    Författare :Rameez Saeed Malik; Olof Karis; Uwe Bovensiepen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetization dynamics; magnetic alloys; HHG; ultrashort laser pulses; magneto-optical Kerr effect MOKE ; Gilbert damping; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis, I investigate the ultrafast magnetization dynamics in 3d ferromagnets and their alloys with ultrashort laser pulses. The high harmonics generation (HHG) setup provides extreme-ultraviolet photons with energies 35-72 eV, which is the energy range where 3d metals have their M2,3 absorption edges. LÄS MER

  3. 2. Algorithms for Molecular Dynamics Simulations

    Författare :Fredrik Hedman; Aatto Laaksonen; Tom Darden; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular dynamics; MD; first principles molecular dynamics; quantum mechanics; liquid water; parallel algorithm; data parallel; MPI; Coulombic interaction; Ewald summation; nonuniform fast Fourier transform; FFT; FFTW; NFFT; ENUF; Physical chemistry; Fysikalisk kemi;

    Sammanfattning : Methods for performing large-scale parallel Molecular Dynamics(MD) simulations are investigated. A perspective on the field of parallel MD simulations is given. Hardware and software aspects are characterized and the interplay between the two is briefly discussed. LÄS MER

  4. 3. On the dynamics of footbridges : A theoretical approach and a comparison between running and walking loads

    Författare :Daniel Colmenares; Raid Karoumi; Andreas Andersson; Mahir Ülker Kaustell; Pedro Museros Romero; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; footbridges; dynamics; human induced loads; human structure interaction; harmonic load; continuous beam; gångbroar; dynamik; fotgängarlast; samverkan mellan fotgängare och bro; harmonisk last; kontinuerlig balk.; Structural Engineering and Bridges; Bro- och stålbyggnad;

    Sammanfattning : The dynamic behaviour of lightweight footbridges is often susceptible to HumanInduced Loads (HILs). Generally HILs are taken into account as moving harmonicfunctions in which the loading frequency represents the step frequency of the pedestrians. LÄS MER

  5. 4. Multi-Resistance Plasmids : Fitness Costs, Dynamics and Evolution

    Författare :Fredrika Rajer; Linus Sandegren; Pål Jarle Johnsen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; multi-resistance plasmids; evolution; fitness cost; dynamics; escherichia coli; ESBL; gene amplification; β-lactamase inhibitor; Biologi med inriktning mot mikrobiologi; Biology with specialization in Microbiology;

    Sammanfattning : Antibiotic resistance is an escalating problem, not only due to less desirable treatment options and outcome, but also due to the economic burden to health care caused by resistant pathogens. Since the process of developing new antibiotics is slow, we need to carefully consider the usage of the antibiotics still available. LÄS MER

  7. 5. Leveraging Intermediate Representations for High-Performance Portable Discrete Fourier Transform Frameworks : with Application to Molecular Dynamics

    Författare :Måns Andersson; Stefano Markidis; Artur Podobas; Niclas Jansson; Ivy Bo Peng; Hartwig Anzt; KTH; []
    Nyckelord :Intermediate Representation; Discrete Fourier Transform; Fast Fourier Transform; Molecular Dynamics; Mellankod; diskret Fouriertransform; snabb Fouriertransform; Molekyldynamik;

    Sammanfattning : The Discrete Fourier Transform (DFT) and its improved formulations, the Fast Fourier Transforms (FFTs), are vital for scientists and engineers in a range of domains from signal processing to the solution of partial differential equations.  A growing trend in Scientific Computing is heterogeneous computing, where accelerators are used instead or together with CPUs. LÄS MER