Search for dissertations about: "transients"

Showing result 1 - 5 of 162 swedish dissertations containing the word transients.

  1. 1. Transients in high head Francis turbines

    Author : Chiragkumar Trivedi; Luleå tekniska universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Francis turbine; load variation; load rejection; start-stop; emergency shutdown; transient; runaway; computational fluid dynamics; runner; transients; blade; power grid; Engineering mechanics - Fluid mechanics; Teknisk mekanik - Strömningsmekanik; Strömningslära; Fluid Mechanics;

    Abstract : On demand energy market and favourable government policies to encourage the usage of renewable energy have led to a dramatic increase of grid connected wind, solar, and other power in recent years. Penetration of the power above manageable limit, produced using intermittent energy sources, to meet the demand has induced instable grid operations. READ MORE

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

    Author : Frédéric Pitout; Ryoichi Fujii; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

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

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

    Abstract : .... READ MORE

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

    Author : Roya Nikjoo; Hans Edin; Christer Törnkvist; KTH; []
    Keywords : 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;

    Abstract : 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. READ MORE

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

    Author : Michael Eberhardson; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE