Search for dissertations about: "near field"

Showing result 6 - 10 of 515 swedish dissertations containing the words near field.

  2. 6. Ultrafast spin, lattice, and electron dynamics in thin metallic films : in the terahertz, near-infrared, and extreme ultraviolet regimes

    Author : Vivek Unikandanunni; Stefano Bonetti; Andreas Rydh; Jurgen Lindner; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Terahertz; near-infrared; extreme ultraviolet; epitaxial cobalt; transient grating; field emission; gold; platinum; electron-phonon coupling; magneto-crystalline anisotropy; nanoscale dynamics; ultrafast spin dynamics; magnetic inertia; nutation; pump-probe; two-temperature model; Fowler-Nordheim tunneling; fysik; Physics;

    Abstract : In this thesis, we studied the ultrafast spin and electron dynamics triggered by electromagnetic radiation belonging to three different regions of the electromagnetic spectrum, namely terahertz, near-infrared and extreme ultraviolet. By performing pump–probe measurements, we explored the role of the lattice in ultrafast spin and electron dynamics in metallic thin films. READ MORE

  4. 7. Defects, renormalization and conformal field theory

    Author : Alexander Söderberg Rousu; Agnese Bissi; Pedro Liendo; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; defects; boundaries; replica twist defect; conformal field theory; quantum field theory; Coleman-Weinberg mechanism; renormalization group flows; Theoretical Physics; Teoretisk fysik;

    Abstract : Defects in quantum field theories appear in many different contexts and are of great physical interest. Among other things, defects are used to describe the Kondō effect in condensed matter, confinement in quantum chromodynamics, Rényi entropy in quantum information and cosmic strings in string theory. READ MORE

  5. 8. Near-Field Study of Multiple Interacting Jets : Confluent Jets

    Author : Shahriar Ghahremanian; Bahram Moshfegh; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple interacting jets; confluent jets; axisymmetric round jet; Low Reynolds number jet; Particle Image Velocimetry PIV ; Laser Doppler Anemometry LDA ; Hot-Wire anemometry HWA ; RANS turbulence models; SST ? − ?; Low Reynolds ? − ?; Response Surface Method;

    Abstract : This thesis deals with the near-field of confluent jets, which can be of interest in many engineering applications such as design of a ventilation supply device. The physical effect of interaction between multiple closely spaced jets is studied using experimental and numerical methods. READ MORE

  6. 9. Photonic terahertz-wave generation, radiation and quasioptical integration

    Author : Biddut Kumar Banik; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semiconductor device modelling; semiconductor diodes; III-V semiconductors; Catadioptric lens; imaging; dipole antennas; slot antennas; lens antennas; semiconductor heterojunctions; dielectric loaded antennas; optical mixers; photomixers; near-field imaging; computer aided engineering; indium compounds; millimetre wave imaging; near-field optics; submillimeter wave generation; photodiodes; terahertz sources; millimetre wave generation; submillimetre wave integrated circuits; microwave imaging; uni-travelling-carrier photodiodes;

    Abstract : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. READ MORE

  7. 10. Visualization of Air Flow, Temperature and Concentration Indoors : Whole-field measuring methods and CFD

    Author : Mathias Cehlin; Mats Sandberg; Alfred Moser; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Environmental engineering; Miljöteknik; Whole-field;

    Abstract : The thermal indoor climate is a complicated combination of a number of physical variables, all of which strongly affect people’s well-being. The indoor climate not only heavily affects people’s health and life quality, but also their productivity and ability to work efficiently. READ MORE