Sökning: "Transients"

Visar resultat 1 - 5 av 166 avhandlingar innehållade ordet Transients.

  1. 1. The Polar Cusp and its Ionospheric footprint : Dynamics and Transients

    Författare :Frédéric Pitout; Ryoichi Fujii; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; Solar wind - magnetosphere - ionosphère interactions; polar ionosphere; Rymd- och plasmafysik; Space physics; Rymdfysik; Space Physics; rymdfysik;

    Sammanfattning : The magnetopause, the boundary layer between the solar wind and the Earth’s magnetosphere, is not closed as we have long thought. Transfers of energy, particles and momentum from the solar wind to the magnetosphere actually take place. LÄS MER

  2. 2. On monitoring voltage transients in medium and low voltage power systems

    Författare :Anna Tjäder; Chalmers University of Technology; []
    Nyckelord :Clarke transformation; ESPRIT; overvoltage; surges; power system; power quality; capacitor switching; transients; power quality monitoring;

    Sammanfattning : .... LÄS MER

  3. 3. Diagnostics of Oil-Impregnated Paper Insulation Systems by Utilizing Lightning and Switching Transients

    Författare :Roya Nikjoo; Hans Edin; Christer Törnkvist; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Capacitance; Dielectric Response; Loss tangent; Moisture content; Oil - impregnated paper; Temperature; Transformer Bushing; Transients;

    Sammanfattning : Development of the power gridtowards a more reliable and smarter system requires frequent on-line monitoring of the power components. Power transformers and their bushings are particularly important components in a power transmission system and their insulation degradation may lead to catastrophic failures. LÄS MER

  4. 4. The interplay of ions in the stimulation of the pancreatic -cell

    Författare :Michael Eberhardson; Uppsala universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cell biology; diabetes; pancreatic β-cells; cytoplasmic calcium; oscillations; glucose; tetrodotoxin; tolbutamide; veratridine; tetraethylammonium; quinine; cesium; H2DIDS; furosemide; transients; microfluorometry; fura-2; MQAE; calcium channels; potassium channels; sodium channels; chloride channels; Cellbiologi; Cell biology; Cellbiologi; medicinsk cellbiologi; Medical Cell Biology;

    Sammanfattning : Glucose stimulation of insulin release is mediated by depolarisation of the pancreatic β-cells with accompanying entry of Ca2+ through voltage-dependent channels. An important feature of the glucose-induced depolarisation is its rhythmicity causing oscillations of the cytoplasmic Ca2+ concentration ([Ca2+]i), which trigger pulsatile release of insulin. LÄS MER

  5. 5. Dielectric Response and Partial Discharge Diagnostics of Insulation Systems by Utilizing High Voltage Impulses

    Författare :Roya Nikjoo; Hans Edin; Andrea Cavallini; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dielectric Response; Transients; Transformer bushing; Oil-impregnated paper; Moisture content; Partial discharge; Surface PD; Cavity PD; Superimposed impulse; Nanoparticles; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, power system transients are considered as an opportunity for development of on-line diagnostics of power components and specifically the insulation systems of power transformers and bushings.A new technique for on-line dielectric response measurement of power transformer bushings is proposed which utilizes natural transients in the power system, such as lightning and switching surges, as stimuli. LÄS MER