Sökning: "Magnetisk"

Visar resultat 41 - 45 av 96 avhandlingar innehållade ordet Magnetisk.

1. 41. Topological excitations in field theory models of superconductivity and magnetism

   Författare :Philipp Rybakov; Egor Babaev; Maxim Mostovoy; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics; Teoretisk fysik; Theoretical Physics;

   Sammanfattning : Topological excitations are subjects of intensive studies in physics and mathematics. In solid-state and soft matter physics, topological excitations can largely determine the thermodynamic and electromagnetic properties of materials, while in high energy physics they were theorized as particles. LÄS MER

3. 42. Design, Modelling and Control of Electrical Machines - With Applications to Iron-powder Machines and Acoustic Noise

   Författare :David Martinez; Industriell elektroteknik och automation; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BEM; induction machine; noise prediction; vector control; acoustic noise; HEV; series magnetization; leakage reduction; thermal model; FEM; MEC; claw-poles; SMC; slip-ring-less machine; sound intensity measurements; vibration; Electrical engineering; Elektroteknik;

   Sammanfattning : This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines. In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. LÄS MER

4. 43. Magnetotransport Studies of Mn Ion-Implanted Nanowires

   Författare :Waldomiro Paschoal; Linnaeus University; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hopping conduction; ferromagnetism; ion-implantation; Nanowire; GaMnAs; magnetoresistance; Fysicumarkivet A:2014:Paschoal;

   Sammanfattning : This thesis focuses on the magnetotransport properties of highly Mn-doped crystalline GaAs nanowires. The GaAs nanowires were first grown by metal-organic vapor phase epitaxy from gold seed particles, and subsequently implanted with Mn ions under varying conditions, e.g., ion fluence and acceleration voltage. LÄS MER

5. 44. Phase Separation in Stainless Steels Studied by Small-angle Neutron Scattering

   Författare :Xin Xu; Peter Hedström; Joakim Odqvist; John Ågren; Cristelle Pareige; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fe-Cr alloys; stainless steels; spinodal decomposition; phase separation; small-angle neutron scattering; mechanical properties; Teknisk materialvetenskap; Materials Science and Engineering;

   Sammanfattning : Fe-Cr based steels, i.e. stainless steels, possessing a combination of excellent corrosion resistance and good mechanical properties, have indispensable applications ranging from low-end cooking utensils, to sophisticated components for nuclear power plants. LÄS MER

7. 45. Proton Magnetic Resonance Spectroscopy in Brain Tumors - Clinical Applications

   Författare :Isabella Björkman-Burtscher; Lund Diagnostisk radiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiology; Clinical physics; Localization; Abscess; Brain; Tumor; Spectroscopy; Magnetic Resonance; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

   Sammanfattning : Aims: · to present a test phantom and test method for evaluation of proton magnetic resonance spectroscopy (1H-MRS) single volume localization techniques regarding signal contamination; · to describe the introduction of 1H-MRS in the daily routine of a standard MR-unit; · to evaluate the possibilities offered by 1H-MRS to improve preoperative diagnostic accuracy in patients scheduled for stereotactic biopsy of intracranial mass lesions; · to evaluate the possibilities offered by 1H-MRS to improve diagnostics and therapy control in patients with brain abscesses; · to test the hypothesis that 1H-MRS might be useful for differentiation of brain tumors, based on metabolic changes in tissue across brain lesions or surrounding tissue. Results and conclusions: · The test phantom and test method allow quality assessment with good reproducibility. LÄS MER