Sökning: "system dynamics"

Visar resultat 31 - 35 av 1910 avhandlingar innehållade orden system dynamics.

  1. 31. Electron-Lattice Dynamics in pi-Conjugated Systems

    Författare :Magnus Hultell (Andersson); Sven Stafström; Alexander Onipko; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polaron dynamics; Exciton dynamics; pi-conjugated systems; Su-Schrieffer-Heeger SSH model; Adiabaticity; Charge carrier transport; Organic electronics.; Computational physics; Beräkningsfysik;

    Sammanfattning : In this thesis we explore in particular the dynamics of a special type of quasi-particle in pi-conjugated materials termed polaron, the origin of which is intimately related to the strong interactions between the electronic and the vibrational degrees of freedom within these systems. In order to conduct such studies with the particular focus of each appended paper, we simultaneously solve the time-dependent Schrödinger equation and the lattice equation of motion with a three-dimensional extension of the famous Su-Schrieffer-Heeger (SSH) model Hamiltonian. LÄS MER

  3. 32. Power System Oscillations - Detection, Estimation and Control

    Författare :Morten Hemmingsson; Industriell elektroteknik och automation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Elektroteknik; oscillation; power system; damping; power swing; distance protection; detection; estimation; real-time; reactive co-variation; control; Electrical engineering; load modulation; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

    Sammanfattning : The topic of this thesis is the electro-mechanical oscillations which to some extent always are present in a power system. The demand of electric power is ever increasing. At the same time, the tolerance of disruptions in the power supply is decreasing. LÄS MER

  4. 33. Magnetization dynamics on the nanoscale : From first principles to atomistic spin dynamics

    Författare :Jonathan Philippe Chico Carpio; Anders Bergman; Samir Lounis; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis first-principles methods, based on density functional theory, have been used to characterize a wide range of magnetic materials. Special emphasis has been put on pairwise magnetic interactions, such as Heisenberg exchange and Dzyaloshinskii-Moriya interactions, and also on in the Gilbert damping parameter. LÄS MER

  5. 34. Dynamics of biological membranes and associated water

    Författare :Peter Berntsen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dielectric spectroscopy; phase transition; glass transition; DSC; lipid bilayers; lipid dynamics; water dynamics; purple membrane; diffusion; polarisation; QENS.; relaxation; long-range conductivity;

    Sammanfattning : An ingenious assembly of biomolecules and water constitute what we call biological tissue. The presence of water in this assembly is fundamental for the physiological processes and can make the difference between life and death. LÄS MER

  7. 35. Navigating interconnected and electrified industries in the landscape of uncertainty : Exploring outcomes and values within circular solutions, and Swedish electricity supply and utilisation dynamics

    Författare :Christoffer Wadström; Maria Johansson; Erik Dahlquist; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Circular system; Outcomes and values in industrial symbiosis; Global economic policy uncertainty; Energy system; Electricity use dynamics;

    Sammanfattning : As the global community faces unprecedented climate change challenges, the transition towards a sustainable society has become an urgent priority. The complexity of this transition is characterised by the interplay of developing and implementing green manufacturing processes, integrated energy systems, and circular resource flows, and the inherent dynamics associated with geopolitical uncertainties, energy price fluctuations, and global instability. LÄS MER