Sökning: "kallt klimat"

Visar resultat 21 - 25 av 34 avhandlingar innehållade orden kallt klimat.

1. 21. 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

3. 22. Low-temperature Heating in Existing Swedish Residential Buildings : Toward Sustainable Retrofitting

   Författare :Qian Wang; Sture Holmberg; Natasa Nord; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Retrofitting; Low-temperature heating; Energy efficiency; Sustainability; Swedish residential buildings; Renovering; Lågtemperatursuppvärmning; Energieffektivitet; Hållbarhet; Svenska bostadsbyggnader; Energy Technology; Energiteknik;

   Sammanfattning : As an energy-efficient alternative in cold climate countries such as Sweden, low-temperature heating (LTH) technology has shown promising advantages and shortcuts to contribute to the efficiency of heat supply, as well as to the overall sustainability of building performance. The goal of this thesis is to contribute to the development of methodologies and modeling tools to support sustainable retrofitting in the Swedish housing stock. LÄS MER

4. 23. Advances in Ventilation Heat Recovery : An assessment of peak loads shaving using renewables

   Författare :Behrouz Nourozi; Sasan Sadrizadeh; Adnan Ploskic; Carey Simonson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Peak heat load shaving; renewable energy; ventilation heat recovery; frosting in heat exchangers; Heat transfer; förnybar energi; ventilation värmeåtervinning; frosting i värmeväxlare; värmeöverföring; Byggvetenskap; Civil and Architectural Engineering;

   Sammanfattning : The building sector accounts for approximately 40% of total global energy usage.In residential buildings located in cold climate countries, 30-60% of this energy isused for space heating, 20–30% is lost by discarded residential wastewater, and therest is devoted to ventilation heat loss. LÄS MER

5. 24. The Ups and Downs of the Holocene: Exploring Relationships between Global CO2 and Climate Variability in the North Atlantic Region

   Författare :Catherine Jessen; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; marklära; geomorfologi; climatology; klimatologi; rapid climate change; Holocene climate; atmospheric CO2 concentrations; geochemical proxy indicators; Paleobotanik; palynology; Geology; palynologi; fylogeni; geomorphology; fysisk geografi; Geologi; physical geography; kartografi; pedology; cartography; phylogeny; Palaeobotany; stomatal frequency; lake sediments;

   Sammanfattning : This thesis aimed to examine the relationship between climate and atmospheric CO2 concentrations through rapid climate changes during the Holocene. Climate was reconstructed using high-resolution, radiocarbon dated, lake sediment geochemical proxies (magnetic susceptibility, loss-on-ignition, total carbon/nitrogen/sulphur determinations and biogenic silica), vegetational reconstruction (pollen analysis) and stomatal frequency based CO2 reconstructions. LÄS MER

7. 25. A systems approach to ice loads on concrete dams

   Författare :Rikard Hellgren; Richard Malm; Anders Ansell; Erik Nordström; Pierre Legér; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ice loads; Ice pressure; Dam safety; Concrete dams; Cold regions; Monitoring; Measurements; Concrete Structures; Betongbyggnad;

   Sammanfattning : Dams are mainly used for the storage of water to electricity production and irrigation, or for river regulation. Continuous work to assure a high dam safety level is a prerequisite to minimize the risk for the uncontrolled release of water. LÄS MER