Sökning: "isbildning"

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet isbildning.

1. 1. Freezing Temperature Flows in Railway Tunnels and its Consequence on the Rock Supporting Structure, the Rock and the Reinforcing Elements

   Författare :Anna Andrén; Lars-Olof Dahlström; Erling Nordlund; Lars O Ericsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tunnel; frost penetration; ice formation; freeze-thaw test; frost shattering; temperature measurement; maintenance; degradation of rock and shotcrete; cold climate; Tunnel; köldinträngning; isbildning; frystester; frostsprängning; temperaturmätning; underhåll; nedbrytning av berg och sprutbetong; kallt klimat; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

   Sammanfattning : Water in the surrounding rock mass flows into the tunnel via naturally occurring joints and via cracks caused by the blasting used to excavate the tunnel. The most common method in Sweden to reduce or prevent leakage problems are first and foremost the use of grouting. LÄS MER

3. 2. Breaking the ice : effects of ice formation and winter floods on vegetation along streams

   Författare :Lovisa Lind; Christer Nilsson; Christine Weber; Michael Scott; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; anchor ice; climate change; in-stream; riparian; river ice; streams; vegetation;

   Sammanfattning : Streams in cold regions are characterized by unique hydrological processes that control flow regime and water levels. One of the most important processes is the formation, growth and melting of different types of ice in and around the stream channel during winter. LÄS MER

4. 3. 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. 4. Local Effects On Icing Forecasts for Wind Power In Cold Climate

   Författare :Erik Janzon; Anna Rutgersson; Metodija Shapkalijevski; Heiner Körnich; Johan Arnqvist; Alfredo Peña; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorologi; Meteorology;

   Sammanfattning : Understanding the risk of atmospheric icing on wind turbines is crucial for the operation of wind farms in cold climate regions. Processes leading to atmospheric icing in the planetary boundary layer are subject to interactions with the land surface--the details of which are largely unknown in current numerical weather prediction models and must be parameterized. LÄS MER

7. 5. Toward Anti-icing and De-icing Surfaces : Effects of Surface Topography and Temperature

   Författare :Golrokh Heydari; Per Claesson; Eric Tyrode; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anti-icing; topography; supercooled water; wetting hysteresis; superhydrophobic; contact angle; nucleation; freezing delay; de-icing; ice adhesion; hydration water; liquid-like layer; smooth; lubrication; anti-is; topografi; underkylt vatten; vätningshysteres; superhydrofob; kontaktvinkel; kärnbildning; avisning; isadhesion; hydrerat vatten; vätskeliknande skikt; smörjning; Kemi; Chemistry;

   Sammanfattning : Icing severely affects society, especially in the Nordic countries. Iceaccumulation can result in critical performance problems and safetyconcerns for instance in road, air and sea transportation, transmissionlines, marine and offshore structures, wind turbines and heat exchangers. LÄS MER