Sökning: "accretion"

Visar resultat 26 - 30 av 68 avhandlingar innehållade ordet accretion.

  1. 26. Frazil ice at water intakes

    Författare :Annika Andersson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : To provide a better understanding of how frazil ice deposits on trash racks at water intakes, the phenomenon was video recorded at two hydropower plants and in a refrigerated laboratory flume. Initial accretion of frazil ice around a single bar and the motion of particles in the vicinity of an obstacle was simulated through numerical modelling and studied using plastic particles in a laboratory flume. LÄS MER

  3. 27. Infants’ Knowledge of Occluded Objects: Evidence of Early Spatiotemporal Representations

    Författare :Gustaf Gredebäck; Claes von Hofsten; Janette Atkinson; Uppsala universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Psychology; infants; occlusion; gaze; object representations; temporal; spatial; associative rule; extrapolation; Psykologi; Psychology; Psykologi;

    Sammanfattning : This thesis demonstrates that infants represent temporarily non-visible, or occluded, objects. From 4 months of age, infants could accurately predict the reappearance of a moving object after 660 ms of non visibility; indicating accurate spatiotemporal representations. LÄS MER

  4. 28. Impact of Icing on Wind Turbines Aerodynamic

    Författare :Narges Tabatabaei; Michel Cervantes; Barakos George N.; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : Wind energy covered 11.6% of Europe electricity demand in 2017. Region with cold climates represent a strong potential for wind energy companies because of their sparse population and proper wind conditions. The global wind energy installations in cold climate regions is forecasted to reach a capacity of 186 GW by the end of 2020. LÄS MER

  5. 29. The Submerged Entry Nozzle : A Study of how to Reduce Decarburization and Clogging

    Författare :Jennie Svensson; Pär Jönsson; Voicu Brabie; Johan Björkvall; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials Science and Engineering; Teknisk materialvetenskap; Steel Forming and Surface Engineering;

    Sammanfattning : During continuous casting the submerged entry nozzle (SEN) is one of the critical points. This since sequence casting is favourable, clogging of the SEN results in fever sequences or aborted castings. In this study the preheating of SEN has been evaluated at different steel plants. LÄS MER

  7. 30. Seyfert-galaxen NGC 7469 : studier av dess aktiva kärna

    Författare :Björn A. M. Westin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : An investigation of the nuclear region in the type 1 Seyfert galaxy NGC 7469 has been made. Optical and ultraviolet spectra obtained for this project have been used, as well as additional ultraviolet spectra and various data from the literature. LÄS MER