Sökning: "Dammar"

Visar resultat 11 - 15 av 40 avhandlingar innehållade ordet Dammar.

  1. 11. Numerical simulations of flow discharge and behaviours in spillways

    Författare :Shicheng Li; Anders Ansell; James Yang; Sébastien Erpicum; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spillway; step geometry; discharge prediction; flow behaviour; machine learning; computational fluid dynamics; Utskov; steggeometri; avbördningsuppskattning; flödesbeteende strömningsegenskap; maskininlärning; flödesdynamisk beräkningsanalys numerisk simulering; Betongbyggnad; Concrete Structures;

    Sammanfattning : A spillway is an important component of a dam and serves as a flood release structure. It achieves controlled discharge of water and protects the dam from overtopping. The majority of the hydropower dams were built before the 1980s, and many spillways are undersized in light of the present design flood guidelines. LÄS MER

  3. 12. Rock mass behavior under hydropower embankment dams with focus on fracture erosion and rock mass stability

    Författare :Alexander Bondarchuk; Ignacio Escuder-Bueno; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : In Sweden there are about 190 large hydropower dams of varying age. According to the definition by the International Commission of Large Dams (ICOLD), if the height of the dam exceeds 15 m it is referred as large. Majority of these dams are of embankment type. LÄS MER

  4. 13. The prey perspective - behaviour and appearance in a world of predators

    Författare :Johan Ahlgren; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Local adaptation; predator regime; phenotypic plasticity; inducible defence; mortality; animal personality; predator; trait-compensation;

    Sammanfattning : The varieties of prey phenotypes that have been revealed in nature are vast and many of these phenotypes are the result of the selective force that predators have had on prey traits in the past. Even within species and populations we see variations due to both differences in the selection forces they live under but also due to individual trait variation. LÄS MER

  5. 14. Urban, pluvial flooding : Blue-green infrastructure as a strategy for resilience

    Författare :Johanna Sörensen; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; urbanhydrologi; pluviala översvämningar; resiliens; blå-grön infrastruktur; socio-teknisk förändring; Urban hydrology; Pluvial flooding; Resilience; Blue-green infrastructure; socio-technical transition;

    Sammanfattning : This thesis investigates urban, pluvial flooding and if blue-green infrastructure, for handling of stormwater in urban green spaces, can be used as a strategy for resilient flood risk management. Spatial analyses of flood claims from insurance companies and the water utility company of Malmö are used to better understand the mechanisms and characteristics of pluvial flooding and how blue-green infrastructure impacts flood risk. LÄS MER

  7. 15. Ecological effects of pesticides in freshwater model ecosystems

    Författare :Lina Wendt-Rasch; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marine biology; aquatic ecology; limnology; Marinbiologi; Hydrobiology; community; zooplankton; algae; herbicide; insecticide; pesticide mixture; macrophytes; cypermethrin; metsulfuron-methyl; risk assessment; pesticides; microcosms; limnologi; akvatisk ekologi;

    Sammanfattning : In this thesis I have investigated the effects of pesticide exposure on the ecosystem level using various types of experimental ecosystems, i.e. microcosms. The direct effect of exposure to cyperemthrin, a pyretroid insecticide, was a rapid decrease of crustancean zooplankton in enclosures in a lake. LÄS MER