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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Karaktäristiken hos strukturmarken på olika altitud i Abiskoområdet – en koppling till klimat och komplex systemteori

   Författare :Gunnar Scharin; Christer Jonasson; Johan Kling; Uppsala universitet; []
   Nyckelord :Abisko; patterned ground; permafrost; non-sorted circles; altitude; self-generation; Geovetenskap med inriktning mot miljöanalys; Earth Science with specialization in Environmental Analysis; Earth Science with specialization in Physical Geography; Geovetenskap med inriktning mot naturgeografi; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   Sammanfattning : Subarctic and alpine areas are sensitive to climatic change when they lie at the margin of permafrost occurrence. Patterned ground in such areas is generated from an interplay among different mechanisms such as temperature, hydrology, soil texture, snow cower and vegetation. LÄS MER

3. 2. Magnetic Order in Artificial Structures

   Författare :Unnar B. Arnalds; Björgvin Hjörvarsson; Sveinn Ólafsson; Vassilios Kapaklis; Hartmut Zabel; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The topic of this thesis is the investigation of the magnetic properties of artificially created magnetic structures. Applying different characterization techniques, ranging from direct imaging methods to reciprocal space techniques, the properties of lithographically patterned arrays of magnetic thin film and multilayer elements are investigated by exploring their magnetic state, extending from the atomic scale up to collective ordering phenomena of nano-magnetic elements. LÄS MER

4. 3. Novel RF MEMS Devices Enabled by Three-Dimensional Micromachining

   Författare :Umer Shah; Joachim Oberhammer; Raafat Mansour; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microelectromechanical systems; MEMS; Radio frequency microelectromechanical systems; RF MEMS; Micromachined transmission line; Micromachining; Tuneable capacitor; Switched capacitor; Coupled-line coupler; Tuneable directional coupler; Intermodulation distortion; MEMS varactor; Two-tone IIP3 measurement; Passive components and circuits; Reliability; Magnetic materials; NiFe multilayer composite; Permeability; Permittivity; Micromachined inductors;

   Sammanfattning : This thesis presents novel radio frequency microelectromechanical (RF MEMS) circuits based on the three-dimensional (3-D) micromachined coplanar transmission lines whose geometry is re-configured by integrated microelectromechanical actuators. Two types of novel RF MEMS devices are proposed. LÄS MER

5. 4. Modeling mesoscopic unconventional superconductors

   Författare :Patric Holmvall; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phase transitions; Andreev bound states; quasiclassical theory; mesoscopic thin-films; spontaneous symmetry breaking; time-reversal symmetry; Unconventional superconductivity; translational symmetry;

   Sammanfattning : High-temperature superconducting materials are often experimentally realized as thin films that can be patterned into devices operating in the mesoscopic regime. On this length scale, various finite-size and surface effects heavily influence the nature of the superconducting state, and can induce new ground states with spontaneously broken symmetries. LÄS MER

7. 5. Tailoring the magnetic order in mesoscopic spin systems

   Författare :Henry Stopfel; Vassilios Kapaklis; Hjörvarsson Björgvin; Unnar Arnalds; John Cumings; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; artificial spin ice; magnetic nano-structures; mesoscopic spin systems; mesospins; model systems; Shakti; Saint George; interaction modifier; engineering of energy-landscape; multiple energy-scales; Fysik; Physics;

   Sammanfattning : Mesoscopic spin systems can be designed and fabricated using modern nano-fabrication techniques. These systems can contain large numbers of patterned ferromagnetic elements, for which the shape will generally determine their effective mesospin dimensionality. LÄS MER