Sökning: "current density distribution"

Visar resultat 21 - 25 av 118 avhandlingar innehållade orden current density distribution.

  1. 21. District Heating for Residential Areas with Single-Family Housing -with Special Emphasis on Domestic Hot Water Comfort

    Författare :Tommy Persson; Energihushållning; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low heat density; District heating; single-family housing; domestic hot water comfort; domestic hot water control; heat losses; supply temperature; thermostatic valves; Energiforskning; Energy research; marketing strategies; market penetration;

    Sammanfattning : The concept of district heating (DH) involves centralised heat production where heat is distributed to consumers via a piping network. It is essential that benefits achieved from concentrated, large-scale production instead of local production in each building exceed the costs associated with heat distribution. LÄS MER

  3. 22. Aromatic Polymers Functionalized with Anionic and Cationic Groups for Ion Exchange Membranes

    Författare :Annika Weiber; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ion exchange membranes; fuel cells; polycondensation; local ion density; poly arylene ether sulfone s;

    Sammanfattning : Fuel cells, redox flow batteries and some water desalination technologies such as reverse osmosis and electrodialysis require efficient ion exchange membranes to perform in an optimum way. Thus, by enhancing the properties of these membranes there is a possibility to improve this type of applications and technologies. LÄS MER

  4. 23. Summer Climate Variability during the Past 1200 Years in Central Scandinavia – A Tree-Ring Perspective

    Författare :Peng Zhang; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Central Scandinavia; climate variability; dendroclimatology; maximum latewood density; Medieval Climate Anomaly; model-proxy data comparison; Pinus sylvestris L.; temperature; tree-ring width;

    Sammanfattning : To set the current 20th century warming in a long-term context, significant efforts have been made to reconstruct hemispheric-to-global temperatures beyond the instrumental period. Tree-rings, which have annual resolution and can be precisely dated, have been widely used to infer past climate variability. LÄS MER

  5. 24. Trees and the environment : Possibilities and challenges in tree-ring research across spatial and temporal scales based on case studies in Sweden

    Författare :Eva Rocha; Steffen Holzkämper; Björn Gunnarson; Anders Moberg; Martin De Luis; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tree rings; Sweden; climate variability; environmental monitoring; ring width; maximum latewood density; stem radial increment; ED-XRF; light rings; Physical Geography; naturgeografi;

    Sammanfattning : The need to understand and quantify the magnitude and frequency of past and current environmental changes increased the demand for high-resolution proxy data across spatial and temporal scales. Due to their long lifespan and global distribution, trees provide a unique and continuous record of environmental variability. LÄS MER

  7. 25. Phase Noise in Communication Systems--Modeling, Compensation, and Performance Analysis

    Författare :M Reza Khanzadi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple antennas; distributed oscillators.; colored phase noise; free-running oscillator; Bayesian Cramér-Rao bound; Oscillator phase noise; phase noise model; channel capacity; mean square error; capacity achieving distribution; Wiener process; extended Kalman filter smoother; maximum a posteriori estimator; phase-locked loop;

    Sammanfattning : The continuous increase in demand for higher data rates due to applications with massive number of users motivates the design of faster and more spectrum efficient communication systems. In theory, the current communication systems must be able to operate close to Shannon capacity bounds. LÄS MER