Sökning: "Björgvin Hjörvarsson"

Visar resultat 6 - 10 av 33 avhandlingar innehållade orden Björgvin Hjörvarsson.

1. 6. Dynamics in magnetic metamaterials

   Författare :Agnė Čiučiulkaitė; Vassilios Kapaklis; Gabriella Andersson; Björgvin Hjörvarsson; Will Branford; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Metamaterials are artificially created structures with properties that are not found in nature. They can be tailored to achieve desired response to external excitations such as external electric and magnetic fields, as well as to enhance materials’ optical or magnetic activity. LÄS MER

3. 7. The effect of nano-confinement on hydrogen uptake in metallic superlattices

   Författare :Sotirios A. Droulias; Max Wolff; Gunnar K. Pálsson; Björgvin Hjörvarsson; Daniel Azofeifa; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The absorption of hydrogen is exothermic in vanadium whereas it is endothermic in iron and chromium. Investigations of the hydrogen uptake within Fe/V(001) and Cr/V(001) superlattices allow therefore a detailed exploration of finite size effects and the influence of boundaries on hydrogen absorption. LÄS MER

4. 8. Amorphous Magnetic Materials : A Versatile Foundation for Tomorrow’s Applications

   Författare :Sebastian George; Gabriella Andersson; Björgvin Hjörvarsson; Fridrik Magnus; Elizabeth Blackburn; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Amorphous; Magnetism; Rare Earth; Transition Metal; RE-TM; Thin Film; TbCo; SmCo; FeZr; CoFeZr;

   Sammanfattning : Amorphous magnetic materials exhibit a number of key differentiating properties with respect to crystalline magnets. In some cases, the differences may simply be in the values of macroscopic properties such as saturation magnetization, coercivity, Curie temperature, and electrical conductivity. LÄS MER

5. 9. Local structure and composition : in additively manufactured bulk metallic glasses and composites

   Författare :Inga Katharina Goetz; Jochen M. Schneider; Björgvin Hjörvarsson; Ulf Jansson; Maria Teresa Pérez Prado; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; additive manufacturing; bulk metallic glasses; nanoscale clustering; convective flow; laser nitriding; laser powder bed fusion; metallic glass - ceramic composites; oxygen impurities; mechanical properties; magnetic properties; viscosity; Fysik; Physics;

   Sammanfattning : Additive manufacturing enables the production of complex multi-material geometries and bulk metallic glass parts beyond their critical casting thickness. The local modification of structure, composition, and properties is explored in this thesis with the aim to design novel composite materials and functional gradients. LÄS MER

7. 10. Hydrogen in nano-sized metals : Diffusion and hysteresis effects

   Författare :Wen Huang; Björgvin Hjörvarsson; Max Wolff; Gavin Walker; Uppsala universitet; []
   Nyckelord :Hydrogen; diffusion; hysteresis; optical technique; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Metal hydrides can be used as hydrogen storage materials for fuel cells and batteries, and as sensors for detecting hydrogen gas. The use of metal hydrides for hydrogen storage can be hindered by poor kinetics and low capacity. Moreover, poor sensitivity, long recovery and response time, limit the applications of metal hydrides as hydrogen sensors. LÄS MER