Sökning: "demagnetization"

Visar resultat 11 - 15 av 28 avhandlingar innehållade ordet demagnetization.

  1. 11. Designing order with long-range interactions in mesoscopic magnetic chains

    Författare :Christina Vantaraki; Vassilios Kapaklis; Björgvin Hjörvarsson; Gabriella Andersson; Tapati Sarkar; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetism; mesospins; mesoscopic magnetic chains; magnetic nanostructures; long-range interactions;

    Sammanfattning : This thesis investigates how the low-energy magnetic configuration of a mesoscopic chain can be tuned by geometrical modifications. The magnetic arrays made by single-domain stadium shaped elements positioned side-by-side were fabricated by patterning into a sputtered ferromagnetic thin film. LÄS MER

  3. 12. Controlled manipulation of microparticles utilizing magnetic and dielectrophoretic forces

    Författare :LarsErik Johansson; Sven Oscarsson; Leif Nyholm; Mälardalens högskola; []
    Nyckelord :Dielectrophoresis; Magnetic beads; MEMS; Micro-particles; Micro-scale manipulation; Micro-system; Biotechnology Chemical Engineering; bioteknik kemiteknik;

    Sammanfattning : This thesis presents some experimental work in the area of manipulation of microparticles. Manipulation of both magnetic and non magnetic beads as well as microorganisms are addressed. The work on magnetic bead manipulation is focused on controlled transport and release, on a micrometer level, of proteins bound to the bead surface. LÄS MER

  4. 13. Design and Assessment of HVDC Off-shore Wind Turbine Generator

    Författare :Poopak Roshanfekr; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; annual energy efficiency.; permanent magnet assisted synchronous reluctance generator PMa-SynRG ; high voltage direct current HVDC ; wind energy; finite element method FEM ; maximum torque per ampere MTPA ; interior permanent magnet synchronous generator IPMSG ;

    Sammanfattning : In this work, design and assessment of a 5 MW wind energy generator with a gearbox is performed to find an energy-efficient generator for HVDC offshore wind turbines, studying aninterior permanent magnet synchronous generator (IPMSG) as well as a permanent magnetassisted synchronous reluctance generator (PMa-SynRG). Quantities such as torque density,torque ripple, losses and amount of magnet material are studied. LÄS MER

  5. 14. Ultrafast resonant magnetic scattering at the European XFEL

    Författare :Nanna Zhou Hagström; Stefano Bonetti; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; XFEL; ultrafast magnetism; holography; SAXS; fysik; Physics;

    Sammanfattning : Magnetic materials are of interest in a wide range of nanotechnologies such as for data storage, memory, logic, and sensing applications. Today, there is a strong desire to manipulate magnetism at timescales below the picosecond. There is therefore a high motivation in studying ultrafast magnetism at the nanoscale. LÄS MER

  7. 15. Modelling approaches for audio frequency power transformers

    Författare :Julius Krah; KTH; []
    Nyckelord :power transformer; audio frequency; loss; hysteresis; eddy currents; skin effect. Leakage inductance;

    Sammanfattning : The development of HVDC converters, local generation andtractions systems increases the demand for power converters.While a lot of studies have been conducted on the powerelectronics, there are still open questions concerning thecontained power transformer that operates at a few kilohertz. LÄS MER