Sökning: "displacement currents"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden displacement currents.

  1. 1. Improvement and Assessment of Two-Dimensional Resistivity Models Derived from Radiomagnetotelluric and Direct-Current Resistivity Data

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Thomas Kalscheuer; Uppsala universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electromagnetic geophysics; radiomagnetotellurics; direct-current resistivity; displacement currents; dielectric effect; non-linearity; inversion; regularization; two-dimensional model; model variance; model resolution; data resolution; NATURAL SCIENCES Physics Other physics Geophysics; NATURVETENSKAP Fysik Övrig fysik Geofysik;

    Sammanfattning : Two-dimensional (2-D) models of electrical resistivity are improved by jointly inverting radiomagnetotelluric (RMT) and direct-current resistivity (DCR) data or by allowing for displacement currents in the inversion of RMT data collected on highly resistive bedrock. Uniqueness and stability of the 2-D models are assessed with a model variance and resolution analysis that allows for the non-linearity of the inverse problem. LÄS MER

  2. 2. ON THE EFFICIENCY OF DISPLACEMENT VENTILATION, with Particular Reference to the Influence of Human Physical Activity

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Magnus Mattsson; Högskolan i Gävle.; KTH.; [1999]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TECHNOLOGY Civil engineering and architecture Building engineering; TEKNIKVETENSKAP Samhällsbyggnadsteknik och arkitektur Byggnadsteknik; Engineering mechanics Fluid mechanics; Teknisk mekanik Strömningsmekanik; Displacement ventilation; Ventilation efficiency; Physical activity; Human activity; Movements; Transient behaviours; Ceiling height; Wall temperature.;

    Sammanfattning : The efficiency of room ventilation by the displacement principle was studied with respect to some influential factors, in particular that of physical activity. The study was experimental and performed in two full-scale test rooms, one of office-size and one of classroom-size. LÄS MER

  3. 3. Modelling the transient response of windings, laminated steel coresand electromagnetic power devices by means of lumped circuits With special reference to windings with a coaxial insulation system

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Pär Holmberg; Uppsala universitet.; [2000]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Transient response; frequency response; electromagnetic transient analysis; circuit modeling; eddy currents; skin effect; windings; coils; magnetic cores; cables; electric machines; rotating electric machines; transformers; Fysik; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik; Electricity; Esp The Study Of Transients and Discharges; elektricitetslära; ssk studiet av transienter och urladdning;

    Sammanfattning : Electromagnetic transients impinging on electromagnetic power devices - such as electric machines, transformers and reactors - can stress the design severely. Thus the magnitudes of the transients are often decisive for the design of the devices. Further, the operation of a device can be transient in itself. LÄS MER

  4. 4. Distribution of Ventilation Air and Heat by Buoyancy Forces inside Buildings An Experimental Study

    Detta är en avhandling från Stockholm : KTH

    Författare :Claes Blomqvist; Högskolan i Gävle.; KTH.; [2009]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TECHNOLOGY Civil engineering and architecture Building engineering; TEKNIKVETENSKAP Samhällsbyggnadsteknik och arkitektur Byggnadsteknik; building ventilation; thermal forces; buoyancy; gravity currents; large openings; heating; air quality; forced convection; free convection;

    Sammanfattning : The main task of the ventilation system in a building is to maintain the air quality and (together with the heating or cooling system) the thermal climate at an acceptable level within the building. This means that a sufficient amount of ventilation air at the appropriate temperature and quality must be supplied to satisfy thermal comfort and air quality demands and that this air is distributed to the parts of the building where people reside. LÄS MER

  5. 5. Characterization of Hydrogeological Media Using Electromagnetic Geophysics

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Niklas Linde; Uppsala universitet.; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Hydrogeophysics; radio magnetotellurics; ground penetrating radar; electrical resistance tomography; inversion; regularization; geostatistics; electrical anisotropy; fractured rock; Geofysik; NATURAL SCIENCES Physics Other physics Geophysics; NATURVETENSKAP Fysik Övrig fysik Geofysik;

    Sammanfattning : Radio magnetotellurics (RMT), crosshole ground penetrating radar (GPR), and crosshole electrical resistance tomography (ERT) were applied in a range of hydrogeological applications where geophysical data could improve hydrogeological characterization.A profile of RMT data collected over highly resistive granite was used to map subhorizontal fracture zones below 300m depth, as well as a steeply dipping fracture zone, which was also observed on a coinciding seismic reflection profile. LÄS MER