Sökning: "polarization"

Visar resultat 21 - 25 av 654 avhandlingar innehållade ordet polarization.

  1. 21. Analysis of Resistor-Loaded Bow-Tie Antennas for Ground Penetrating Radar Applications

    Författare :Disala Uduwawala; KTH; []
    Nyckelord :Ground penetrating radar; Buried object detection; Simulation; Radar antennas; Radar signal processing; FDTD methods; Optimal design; Lossy media; Dispersive media; Clutter; Polarization;

    Sammanfattning : Ground penetrating radar (GPR) systems are increasinglybeing used for the detection and location of buried objectswithin the upper regions of the earth's surface. Numericalsimulation of such systems plays an important role in thedevelopment of GPR hardware and signal processingtechniques. LÄS MER

  3. 22. An Experimental and Theoretical Study of the Mass Transport in Lithium-Ion Battery Electrolytes

    Författare :Andreas Nyman; Göran Lindbergh; Mårten Behm; Signe Kjelstrup; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lithium‐ion batteries; Electrolytes; Transport properties; Conductivity; Diffusion coefficients; Transport number; Maxwell-Stefan equation; Simulations; Mathematical analysis; Polarization; Hybrid electric vehicles; Litiumjonbatterier; Aprotiska elektrolyter; Transport egenskaper; Konduktivitet; Diffusion koefficienter; Transporttal; Maxwell-Stefans ekvation; Simuleringar; Matematisk analys; Polarisation; Elhybridfordon; Electrochemistry; Elektrokemi;

    Sammanfattning : Lithium‐ion batteries are particularly suitable as energy storage solutions in high power applications, such as hybrid electric vehicles. It is generally considered that one of the processes that limit the power density for lithium‐ion batteries is the mass transport in the electrolyte. LÄS MER

  4. 23. Development and Characterisation of Cathode Materials for the Molten Carbonate Fuel Cell

    Författare :Athula Wijayasinghe; KTH; []
    Nyckelord :molten carbonate fuel cell MCFC ; MCFC cathode; LiFeO2-LiCoO2-NiO ternary compositions; electrical conductivity; porous gas diffusion electrodes; polarization; electrochemical performance; post-cell characterization;

    Sammanfattning : Among the obstacles for the commercialization of the MoltenCarbonate Fuel Cell (MCFC), the dissolution of thestate-of-the-art lithiated NiO cathode is considered as aprimary lifetime limiting constraint. Development ofalternative cathode materials is considered as a main strategyfor solving the cathode dissolution problem. LÄS MER

  5. 24. Mathematical Models for Investigation of Performance, Safety, and Aging in Lithium-Ion Batteries

    Författare :Tommy Georgios Zavalis; Göran Lindbergh; Mårten Behm; Yann Bultel; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lithium-ion battery; modeling; electrochemical processes; impedance; polarization; performance; safety; aging; power optimized battery; litiumjonbatteri; modellering; elektrokemiska processer; impedans; polarisation; prestanda; säkerhet; åldring; effektoptimerat batteri;

    Sammanfattning : Rechargeable lithium-ion batteries have both the power and energy capabilities to be utilized in hybrid electric vehicles and other power demanding applications. However, there are obstacles primarily related to reliability in safety and lifetime. Additionally, there is still room for improvement in the battery performance. LÄS MER

  7. 25. Optical spectroscopy of InGaAs quantum dots

    Författare :Arvid Larsson; Per Olof Holtz; Artur Zrenner; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; quantum dot; semiconductor; optical properties; spin; transport; wetting layer; polarization; kvantprick; halvledare; optiska egenskaper; spin; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Materials science; Teknisk materialvetenskap; Condensed matter physics; Kondenserade materiens fysik; Semiconductor physics; Halvledarfysik;

    Sammanfattning : The work presented in this thesis deals with optical studies of semiconductor quantum dots (QDs) in the InGaAs material system. It is shown that for self-assembled InAs QDs, the interaction with the surrounding GaAs barrier and the InAs wetting layer (WL) in particular, has a very large impact on their optical properties. LÄS MER