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Visar resultat 1 - 5 av 31 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Tearing mode dynamics in the presence of resonant magnetic perturbations

   Författare :Richard Fridström; Per Brunsell; Marco Cecconello; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tearing mode; plasma; fusion; reversed-field pinch; RFP; magnetic; confinement; resonant; perturbation; magnetohydrodynamics; MHD; EXTRAP T2R; Madison Symmetic Torus; Fysik; Physics;

   Sammanfattning : Magnetically confined fusion (MCF) plasmas are typically subject to several unstable modes. The growth of one mode can limit the plasma energy confinement and might cause a termination of the plasma. Externally applied resonant magnetic perturbations (RMPs) are used to control and to mitigate some of the unstable modes. LÄS MER

3. 2. Tunable Magnetic Properties of Transition Metal Compounds

   Författare :Solveig Felton; Per Nordblad; Peter Svedlindh; John Chapman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetic properties; Transition metal compounds; Magnetic structure; Domain structure; SQUID-magnetometry; MFM; Magnetism; Magnetism;

   Sammanfattning : The magnetic properties of transition metal compounds have been studied using SQUID-magnetometry, magnetic force microscopy and Lorentz transmission electron microscopy. New magnetic materials have been found and their magnetic properties have been determined. How the magnetic properties of a material can be changed through e.g. LÄS MER

4. 3. Improving the functionality of synchronous machines using power electronics

   Författare :Fredrik Evestedt; Urban Lundin; C. Johan. D. Abrahamsson; Jon Kjellin; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power electronics; Synchronous machines; Excitation systems; Magnetic thrust bearing; Starting synchronous machines; Split rotor; Rotating electronics; Magnetic fields; Measurement systems; Unbalanced magnetic pull; Harmonics; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : With the advent of modern power electronics there is reason to explore what can be achieved when it is applied to a mature technology like synchronous machines. In this text several concepts will be presented on how it is possible to control forces and how to get better performance out of synchronous machines by using power electronics. LÄS MER

5. 4. Magnetic Nanoparticle Based Biosensors for Pathogen Detection and Cancer Diagnostics

   Författare :Bo Tian; Mattias Strömberg; Peter Svedlindh; Hakho Lee; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetic biosensors; magnetic nanoparticles; homogeneous assays; volumetric sensing; Engineering Science with specialization in Solid State Physics; Teknisk fysik med inriktning mot fasta tillståndets fysik;

   Sammanfattning : This thesis describes several magnetic nanoparticle (MNP)-based biosensing strategies which take advantage of different magnetic sensors, molecular tools and nanotechnologies. Proposed biosensors can be classified into three groups, i.e., immunoassay-based, molecular amplification-based, and nanoparticle assembly-based. LÄS MER

7. 5. Measurement and modelling of unbalanced magnetic pull in hydropower generators

   Författare :Mattias Wallin; Urban Lundin; Antero Arkkio; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Damper winding; eddy currents; field winding short circuit; finite element method; hydropower generator; parallel circuits; rotor eccentricity; salient poles; synchronous generators; synchronous machines; UMP; unbalanced magnetic pull.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Hydropower research is often perceived to be an old and exhausted field of study but with ageing equipment and the need for more intermittent operation caused by an increased share of other renewable energy sources new challenges lie ahead.The main focus of this dissertation are the electromagnetic forces resulting from nonuniform air gap flux, whether it be caused by rotor eccentricity or a faulty field winding. LÄS MER