Sökning: "dielectric function"

Visar resultat 21 - 25 av 77 avhandlingar innehållade orden dielectric function.

  1. 21. Photonic THz Generation and Quasioptical Integration for Imaging Applications

    Författare :Biddut Kumar Banik; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nondestructive evaluation; semiconductor device modelling; uni-travelling-carrier photodiodes; millimetre wave and submillimetre wave generation; III-V semiconductors; photomixers; terahertz sources.; catadioptric lens; microwave imaging; dielectric loaded antennas; terahertz imaging; lens antennas; millimetre wave and submillimetre wave imaging;

    Sammanfattning : This thesis deals with the analysis and optimisation of the uni-travelling-carrier photodiode (UTC-PD) for continuous-wave generation in terahertz (THz) frequencyrange. Photonic THz generation using UTC-PDs is extremely promising as it offers wide tunability, adequate output power and room temperature operation. LÄS MER

  3. 22. Studies of magnetic multi-core nanoparticles for biomedical applications

    Författare :Vincent Schaller; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Metropolis algorithm; magnetic bioseparation; Monte Carlo method; Brownian dynamics; magnetic immunoassays; Magnetic multi-core nanoparticles; digital microfluidics; electrowetting-on-dielectric EWOD ;

    Sammanfattning : In recent years, there has been growing interest in using magnetic multi-core nanoparticles in biomedical applications, and particularly in bioseparation and biosensing. In this thesis, two computer simulation techniques have been implemented to study the magnetic response of these particles, and a microfluidic platform has been fabricated to manipulate bio-functionalized magnetic particles in suspension for immunoassays. LÄS MER

  4. 23. Analysis and Design of Conformal Array Antennas

    Författare :Patrik Persson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Conformal antennas; conformal arrays; UTD; high frequency method; MoM; hybrid method; mutual coupling; singly curved surface; doubly curved surface; geodesics; dielectric covered circular cylinder; non-paraxial region. paraxial region; waveguide fed; Electrical engineering; Elektroteknik;

    Sammanfattning : Today there is a great need for communication between people and even between things, using systems onboard e.g. aircraft, cars, ships and satellites. As a consequence, these communications needs require antennas mounted on or integrated in the surfaces of different vehicles or platforms, i. LÄS MER

  5. 24. First principles study of oxide semiconductors for solar energy applications

    Författare :Maofeng Dou; Clas Persson; Huda Muhammad N.; Sergey Simak; Anna Delin; Peter Johansson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photocatalysis; water splitting; oxynitrides; dielectric function; first-principles calculation; density functional theory; electronic structures; Casimir interaction; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The objectives of this thesis are to understand the electronic structures of oxides and oxynitrides for photocatalytic water splitting, examine the Casimir interaction between oxides, and explore possible approach to bridge the Casimir force and material properties for advanced material research. The studies were performed in the framework of the density functional theory, many-body perturbation theory, i. LÄS MER

  7. 25. Optical Studies of Periodic Microstructures in Polar Materials

    Författare :Herman Högström; Carl Gustaf Ribbing; Clivia M. Sotomayor Torres; Uppsala universitet; []
    Nyckelord :Engineering physics; polaritonic; polar; photonic crystal; surface phonon polariton; multilayer; Reststrahlen; SiC; SiO2; Teknisk fysik;

    Sammanfattning : The optical properties of matter are determined by the coupling of the incident electromagnetic radiation to oscillators within the material. The oscillators can be electrons, ions or molecules. Close to a resonance the dielectric function exhibits strong dispersion and may be negative. LÄS MER