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Visar resultat 1 - 5 av 17 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. The Complex World of Superstrings : On Semichiral Sigma Models and N=(4,4) Supersymmetry

    Författare :Malin Göteman; Ulf Lindström; Daniel Waldram; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-linear sigma models; extended supersymmetry; semichiral superfields; neutral hyperkähler geometry; generalized Kähler geometry; T-duality; vector multiplets; Theoretical Physics; Teoretisk fysik;

    Sammanfattning : Non-linear sigma models with extended supersymmetry have constrained target space geometries, and can serve as effective tools for investigating and constructing new geometries. Analyzing the geometrical and topological properties of sigma models is necessary to understand the underlying structures of string theory. LÄS MER

  3. 2. Strings as Sigma Models and in the Tensionless Limit

    Författare :Jonas Persson; Ulf Lindström; Joseph Minahan; Fawad Hassan; Uppsala universitet; []
    Nyckelord :Theoretical physics; Theoretical Physics; String Theory; Tensionless Strings; Supergravity Backgrounds; Plane Wave; Extended Supersymmetry; Non-Linear Sigma Models; Generalized Complex Geometry; T-duality; Teoretisk fysik;

    Sammanfattning : This thesis considers two different aspects of string theory, the tensionless limit of the string and supersymmetric sigma models with extended supersymmetry. First, the tensionless limit is used to find a IIB supergravity background generated by a tensionless string. The background has the characteristics of a gravitational shock-wave. LÄS MER

  4. 3. Understanding as experiencing a pattern

    Författare :Paulina Lindström; Kognitionsvetenskap; []
    Nyckelord :HUMANIORA; HUMANITIES; Understanding; eye-tracking; mathematical problem solving; cognition; pedagogy;

    Sammanfattning : The thesis proposes that understanding is a matter of experiencing a pattern. To experience a pattern involves seeing how a task, principle, or problem space is structured; to attend to the relevant information; and to be able to use that information as it relates to the knowledge domain at hand. LÄS MER

  5. 4. d-wave Josephson Junctions

    Författare :Tobias Lindström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson junctions; high-temperature superconductivity; Andreev states;

    Sammanfattning : The properties of d-wave YBCO Josephson junctions and dc-SQUIDs with high misorientation angles have beenstudied experimentally .The predominant d-wave symmetry of the pairing wavefunction in high-Tc superconductors has, to a large extent, beena hinderance in applications, but it also makes it possible to fabricate devices with novel properties that may be suitablefor applications in the quantum regime; one particulary interesting property is a strong second harmonic component in the current-phase relation ofjunctions with the electrodes oriented in a node-lobe arrangement; so-called 0-45 junctions. LÄS MER

  7. 5. Adrenocorticolysis Induced by 3-MeSO2-DDE : Mechanisms of Action, Kinetics and Species Differences

    Författare :Veronica Lindström; Ingvar Brandt; Ulrika Bergström; Eva Brittebo; Hans Tjälve; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Toxicology; 3-methylsulphonyl-DDE; o; p -DDD; CYP11B1; adrenal cortex; tissue-specific toxicity; bioactivation; kinetics; Y-1 cells; Toxikologi; Biology; Biologi;

    Sammanfattning : The DDT metabolite 3-methylsulphonyl-DDE (3-MeSO2-DDE) induces cell death specifically in the adrenal cortex of mice after a cytochrome P45011B1 (CYP11B1)-catalysed bioactivation. This substance is not only an environmental pollutant, but also a suggested lead compound for an improved chemotherapy of adrenocortical carcinoma (ACC). LÄS MER