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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Nonlinear Dynamics of Coherent and Partially Coherent Optical Waves

    Författare :Tobias Hansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; soliton interaction; Wigner transform; logarithmically saturable media; Nonlinear Schrödinger equation; parabolic beams; partial coherence; quasilinear diffusion; modulational instability;

    Sammanfattning : In optics an important nonlinear effect is manifested by the fact that the refractive index, in addition to its frequency dependence, also depends on the intensity of the light. Nonlinear effects are present within a wide range of optical applications e.g. the fast growing fields of fiber-optic communication and all-optical signal processing. LÄS MER

  3. 2. Nonlinear Theory of Partially Coherent Optical Waves

    Författare :Tobias Hansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; partial coherence; beam collapse; saturable logarithmic media; soliton interaction; dressing method; parabolic beams; Wigner transform; invariants; modulational instability;

    Sammanfattning : Nonlinear effects arise in optics as a consequence of the medium properties being modified by the presence of light. Of particular interest are situations where the effect of the nonlinearity can be described by an intensity dependent refractive index and the subsequent interplay with dispersion and diffraction. LÄS MER

  4. 3. Objects in Time : Studies of Persistence in B-time

    Författare :Tobias Hansson Wahlberg; Teoretisk filosofi; []
    Nyckelord :HUMANIORA; HUMANITIES; B-time; three-dimensionalism.; stage theory; tenselessness; persistence; perdurance; mereology; four-dimensionalism; dispositions; endurance; B-theory of time; change; temporary intrinsics;

    Sammanfattning : This thesis is about the conceptualization of persistence of physical, middle-sized objects within the theoretical framework of the revisionary ‘B-theory’ of time. According to the B-theory, time does not flow, but is an extended and inherently directed fourth dimension along which the history of the universe is ‘laid out’ once and for all. LÄS MER

  5. 4. Prolonged Drug Release from Gels, using Catanionic Mixtures

    Författare :Tobias Bramer; Katarina Edsman; Per Hansson; Stefan Ulvenlund; Uppsala universitet; []
    Nyckelord :Pharmaceutics; gel; catanionic; vesicle; micelle; controlled release; diffusion; surfactant; drug delivery; Galenisk farmaci;

    Sammanfattning : The use of catanionic drug-surfactant mixtures was proven to be an efficient novel method of obtaining prolonged drug release from gels. It was shown that various commonly used drug compounds are able to form catanionic mixtures together with oppositely charged surfactants. LÄS MER

  7. 5. Neurosteroids Induce Allosteric Effects on the NMDA Receptor : Nanomolar Concentrations of Neurosteroids Exert Non-Genomic Effects on the NMDA Receptor Complex

    Författare :Tobias Johansson; Fred Nyberg; Pierre Le Grevès; Elisabeth Hansson; Uppsala universitet; []
    Nyckelord :Pharmaceutical pharmacology; Pharmacology; neurosteroids; NMDA receptor; NR2B subunit; ifenprodil; sigma receptor; anabolic androgenic steroids; allosteric modulation; non-genomic; Farmaceutisk farmakologi;

    Sammanfattning : The neurosteroids constitute a group of powerful hormones synthesized and acting in the central nervous system. They participate in a number of important central processes, such as memory and learning, mood and neuroprotection. LÄS MER