Avancerad sökning

Visar resultat 21 - 25 av 350 avhandlingar som matchar ovanstående sökkriterier.

  1. 21. Fatigue improvement of steel bridges with high-frequency mechanical impact treatment

    Författare :Poja Shams Hakimi; 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; HFMI; thickness effect; bridge; steel; variable amplitude; fatigue;

    Sammanfattning : This thesis investigates the performance of fatigue-improved welds with high-frequency mechanical impact (HFMI) for application on new bridges. Fatigue strength improvement with HFMI can enable lightweight design of bridges and allow the utilisation of the benefits of high-strength steels. LÄS MER

  3. 22. High Frequency Model of Electrified Railway Propulsion System for EMC Analysis

    Författare :Kelin Jia; Rajeev Thottappillil; Hans Bängtsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; railway; propulsion system; multitransmission line; ac motor modeling; vector fitting; fast transient;

    Sammanfattning : A model of the electrified railway propulsion system working in a wide frequency range is studied in this thesis. The high frequency modeling is the first stage to study and predict the Electromagnetic compatibility (EMC) problems in the electrified railway propulsion system, which are safety and reliability issues of high concern. LÄS MER

  4. 23. Pulsed Electric Field Food Treatment and Low Frequency Bioelectromagnetics

    Författare :Martin Lindgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; extremely low frequency; non-thermal microbial inactivation; electromagnetic fields; biological effects; treatment chambers; electric field distribution; magnetic fields; pulsed electric fields;

    Sammanfattning : This thesis is divided in two parts, both of which address the interaction between biological cells (especially cell membranes) and electromagnetic fields. The first part deals with the application of intense pulsed electric fields (PEF) in foods. It is intended to be a non-thermal method to inactivate microorganisms. LÄS MER

  5. 24. The environment of high-redshift AGN

    Författare :Judit Fogasy; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : In order to understand the formation and evolution of local massive galaxies and to reveal the processes that engineered the tight correlations found between their supermassive black hole (SMBH) mass and bulge mass or velocity dispersion, the study of powerful, high-redshift active galactic nuclei (AGN) and their environment is crucial. Observations of high-z quasars and radio galaxies suggest that these AGN live in overdense environment surrounding by star-forming Ly&alpha-emitters and submillimeter galaxies. LÄS MER

  7. 25. Computer methods for voice analysis

    Författare :Svante Granqvist; KTH; []
    Nyckelord :voice analysis; perceptual analysis; fundamental frequency; correlogram; aperiodicity; Fourier analysis; high-speed imaging; laryngoscopy; vocal fold vibration; voice accumulation.; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : This thesis consists of five articles and a summary. Thethesis deals with methods for measuring properties of thevoice. The methods are all computer-based, but utilisedifferent approaches for measuring different aspects of thevoice. Paper I introduces the Visual Sort and Rate (VSR) method forperceptual rating of voice quality. LÄS MER