Search for dissertations about: "External field"

Showing result 1 - 5 of 484 swedish dissertations containing the words External field.

  2. 1. Determination of the thermal conductivity of the insulation in district heating mains : Field measurements

    Author : Karin Margaretha Borgström; Högskolan i Halmstad; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; district heating main; field measurements; thermal conductivity; measuring method; heat flow measurement; heat flux sensor; Material physics with surface physics; Materialfysik med ytfysik;

    Abstract : This thesis concerns the development of a measurement method for determination in the field of the thermal conductivity of the insulation in buried district heating mains. The thermal conductivity of the insulation is calculated from the measured value of the radial heat flow through the heating main, the measured temperature difference across the insulation, and the dimensions of the heating main. READ MORE

  4. 2. External Mycelia of Mycorrhizal Fungi - responses to elevated N in forest ecosystems

    Author : Lars Ola Nilsson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ericoid; arbuscular; mycorrhiza; nitrogen; deposition; fertilisation; nitrate leaching; retention; field; forest; Quercus; deciduous; Plant ecology; Växtekologi; mykologi; virologi; bakteriologi; mycology; Microbiology; External mycelia; ectomycorrhiza; Mikrobiologi; bacteriology; virology;

    Abstract : Most plants live in symbiosis with mycorrhizal fungi. Mycorrhizal roots constitute the interface between the plant and the soil, and almost every fine root of forest trees in nitrogen-limited boreal and temperate forests is colonised by ectomycorrhizal (EM) fungi. READ MORE

  5. 3. Resonant magnetic perturbation effect on the tearing mode dynamics : Novel measurements and modeling of magnetic fluctuation induced momentum transport in the reversed-field pinch

    Author : Richard Fridström; Per Brunsell; Lorenzo Frassinetti; Tommaso Bolzonella; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; RFP; reversed-field pinch; tokamak; tearing mode; RMP; fusion; plasma; resonant magnetic perturbation; stochastic; magnetic; field; viscosity; mode; locking; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The tearing mode (TM) is a resistive instability that can arise in magnetically confined plasmas. The TM can be driven unstable by the gradient of the plasma current. When the mode grows it destroys the magnetic field symmetry and reconnects the magnetic field in the form of a so-called magnetic island. READ MORE

  6. 4. Schwinger terms in external field problems

    Author : Christian Ekstrand; KTH; []
    Keywords : ;

    Abstract : .... READ MORE

  7. 5. Non-Perturbative Quantum Field Theory in Extreme Environments

    Author : Per Liljenberg; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; pair production; Bose-Einstein condensation; functional representation; Schwinger model; external field; boson stars; temperature; magnetisation;

    Abstract : The aim of this thesis is to describe some physical systems which can be treated by non-perturbative methods in quantum field theory. In the thesis we study systems described by quadratic Hamiltonians, possibly extended with an external electromagnetic field and/or with a thermal heat bath. READ MORE