Sökning: "periodic structure"

Visar resultat 6 - 10 av 165 avhandlingar innehållade orden periodic structure.

  1. 6. Twist-Symmetric Periodic Structures : Properties and Applications

    Författare :Oskar Zetterström; Oscar Quevedo-Teruel; Martin Norgren; Nelson Fonseca; Jorge Ruiz-Cruz; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, periodic structures with higher symmetries symmetries are discussed. The main focus of the thesis is on twist symmetries. Importantly, the attractive properties of twist symmetries for the control of electromagnetic wave propagation are demonstrated. LÄS MER

  3. 7. Computer Simulations of Polymer Gels : Structure, Dynamics, and Deformation

    Författare :Natasha Kamerlin; Christer Elvingson; Jan Forsman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; computer simulations; Brownian dynamics; polymer gel; microgel; spherical boundary conditions; hypersphere; core-shell; deswelling; mechanical properties; uniaxial elongation;

    Sammanfattning : This thesis presents the results of computer simulation studies of the structure, dynamics, and deformation of cross-linked polymer gels. Obtaining a fundamental understanding of the interrelation between the detailed structure and the properties of polymer gels is a challenge and a key issue towards designing materials for specific purposes. LÄS MER

  4. 8. Periodic Structures with Higher Symmetries: Analysis and Applications

    Författare :Fatemeh Ghasemifard; Martin Norgren; Oscar Quevedo-Teruel; Guido Valerio; Stefano Maci; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. LÄS MER

  5. 9. In pursuit of next generation photovoltaics : An electronic structure study of emerging solar cell materials

    Författare :Axel Erbing; Michael Odelius; David Scanlon; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Solar cells; computational physics; density functional theory; electronic structure; molecular dynamics; Solceller; beräkningsfysik; täthetsfunktionalteori; elektronstruktur; molekyldynamik; Theoretical Physics; teoretisk fysik;

    Sammanfattning : The development of a new generation of photovoltaic technologies is an important task in order to increase the production of clean energy. Perovskite solar cells, with an exceptionally rapid development over the last decade, have transformed into perhaps the most promising candidate to provide a low-cost alternative to conventional cells. LÄS MER

  7. 10. Numerical Studies of Energy Gaps in Photonic Crystals

    Författare :Andreas Rung; Carl-Gustaf Ribbing; Norbert Kaiser; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; photonic crystals; polaritonic; periodic structures; Reststrahlen; band structure; energy gap; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The concept of photonic crystals was born in the late 1980's when two important letters were published that showed the possibility to control light propagation by a periodic structure. A photonic crystals consists of two or more materials with different dielectric functions periodically arranged on the length scale of light. LÄS MER