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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Calculations of defect related properties in semiconductors

    Författare :Sven Öberg; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Scientific Computing; Teknisk-vetenskapliga beräkningar;

    Sammanfattning : Many of the most important and useful properties of crystalline materials, such as mechanical strength and electrical resistance, are determined by the presence of lattice defects and impurities. Well known examples are dislocations which control plastic flow and make metals ductile, and dopant atoms which control the extrinsic conduction in semiconductors and insulators. LÄS MER

  2. 2. Bone Healing after implantation of bone substitute materials. Experimental studies in estrogen deficiency

    Författare :Sven Öberg; Jan Rosenquist; Ulf Lekholm; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Surgery; Bone grafts; hydroxyapatite; estrogen deficiency; demineralised bone; bone formation; AAA bone; bone defect; titanium implants; resonance frequency analysis.; Kirurgi; Surgery; Kirurgi; kirurgi; Surgery;

    Sammanfattning : Bone formation and bone healing were studied in the mandible, tibia and skull bones in adult, healthy and estrogen deficient rabbits implanted with different bone substitutes.In the first study an evaluation of the differences in bone regeneration in and around solid (Alveograf *) and porous hydroxyapatite (Interpore 200*) was undertaken. LÄS MER

  3. 3. A Theoretical Study: The Connection between Stability of Single-Walled Carbon Nanotubes and Observed Products

    Författare :Daniel Hedman; Andreas Larsson; Sven Öberg; Krisztián Kordás; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Single-walled carbon nanotubes; density functional theory; catalytic chemical vapor deposition; chirality-specific growth; stability; length; diameter; edge; chirality; Applied Physics; Tillämpad fysik;

    Sammanfattning : Over the past 20 years’ researchers have tried to utilize the remarkable properties of single-walled carbon nanotubes (SWCNTs) to create new high-tech materials and devices, such as strong light-weight composites, efficient electrical wires and super-fast transistors. But the mass production of these materials and devices are still hampered by the poor uniformity of the produced SWCNTs. LÄS MER

  4. 4. Single-Walled Carbon Nanotubes : A theoretical study of stability, growth and properties

    Författare :Daniel Hedman; Andreas Larsson; Sven Öberg; Esko I. Kauppinen; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Applied Physics; Tillämpad fysik;

    Sammanfattning : Since their discovery over 25 years ago, scientists have explored the remarkable properties of single-walled carbon nanotubes (SWCNTs) for use in high-tech materials and devices, such as strong light-weight composites, efficient electrical wires, supercapacitors and high-speed transistors. However, the mass production of such materials and devices is still limited by the capability of producing uniform high-quality SWCNTs. LÄS MER

  5. 5. A Theoretical Investigation of the Nitrogen-Vacancy Center in Diamond as a Single Molecule Sensor and Qubit : Charging through Explicit Electron Donors

    Författare :Robin Löfgren; Andreas Larsson; Sven Öberg; Corina Etz; Fedor Jelezko; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Applied Physics; Tillämpad fysik;

    Sammanfattning : The NV-center in diamond is one of the most well researched defects to date. Since its discovery in the 1960’s, a large body of experimental as well as theoretical work have been produced, investigating its properties and applications. LÄS MER