Sökning: "natural disturbances"

Visar resultat 16 - 20 av 229 avhandlingar innehållade orden natural disturbances.

  1. 16. Measurements and Modelling of Low-frequency Disturbances in Induction Machines

    Författare :Torbjörn Thiringer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modelling; induction machine; measurements;

    Sammanfattning : in this thesis the low-frequency dynamic behavior of the induction machine is analyzed. disturbances in the shaft torque and supply voltage are investigated theoretically, The calculated response to shaft torque disturbances is verified with measurements on a 15 kW machine. LÄS MER

  3. 17. On the impact of temperature perturbations on the creep of sensitive clay

    Författare :Yanling Li; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; thermal cycles; sensitive clays; oedometer tests; temperature; natural bonding; apparent preconsolidation pressure; multi-physics modelling; geothermal; static thermal loading;

    Sammanfattning : Temperature affects the soil response, but is not fully understood and quantified and thus often ignored. The temperature fluctuations resulting from energy foundations and construction activities, such as excavations and soil stabilization, however, may lead to changes in the hydromechanical response of the clay. LÄS MER

  4. 18. On optimization of natural convection flows

    Författare :Clio Saglietti; Dan S. Henningson; Kurt Maute; KTH; []
    Nyckelord :Natural convection cooling; topology optimization; flow optimization; heat sink; conjugate heat transfer; differentially heated cavity; optimal initial disturbances; adjoint optimization;

    Sammanfattning : Two different techniques are presented for enhancing the thermal  performance of natural convection cooled heat sinks. The physics is  described by solving the conjugate heat transfer problem with a  spectral element method. The temperature distribution is computed in  two sub-domains, whose solution is then conjugated. LÄS MER

  5. 19. Trends and exposure of naturally produced brominated substances in Baltic biota - with focus on OH-PBDEs, MeO-PBDEs and PBDDs

    Författare :Karin Löfstrand; Lillemor Asplund; Åke Bergman; Adrian Covaci; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Batlic Sea; Natural production; OH-PBDE; MeO-PBDE; PBDD; Environmental chemistry; Miljökemi; miljökemi; Environmental Chemistry;

    Sammanfattning : The semi-enclosed and brackish Baltic Sea has become heavily polluted by nutrients, anthropogenic organic and inorganic chemicals via human activities. Persistent organic pollutants (POPs) have been thoroughly investigated due to their linkage to toxic effects observed in Baltic biota. There has been far less focus on semi-persistent pollutants e. LÄS MER

  7. 20. On the intra-seasonal to decadal climate variability over South-Asia

    Författare :Faisal Saeed Syed; Heiner Körnich; Erik Kjellström; Jagadish Shukla; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; South Asia; monsoon; western disturbances; fog; climate variability; climate dynamics; teleconnections; ENSO; NAO; CGT; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : South Asia, a land of contrasting landscapes, seasons and climates, is highly vulnerable to climate variability over intra-seasonal to decadal time scales. In winter, precipitation over the western parts of south Asia and fog over the Indo-Gangetic (IG) plains are the two major climatic features. LÄS MER