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Showing result 1 - 5 of 246 swedish dissertations matching the above criteria.

  2. 1. Higher order differential operators on graphs

    Author : Jacob Muller; Pavel Kurasov; Ram Band; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Almost periodic functions; differential operators on metric graphs; quantum graphs; estimation of eigenvalues;

    Abstract : This thesis consists of two papers, enumerated by Roman numerals. The main focus is on the spectral theory of -Laplacians. Here, an -Laplacian, for integer , refers to a metric graph equipped with a differential operator whose differential expression is the -th derivative. READ MORE

  4. 2. Optical characterization of wide band gap materials by spectroscopic ellipsometry

    Author : O. P. Alexander Lindquist; Linköpings universitet; []
    Keywords : Wide Band Gap materials; ellipsometry; SiC; GaN;

    Abstract : Spectroscopic ellipsometry has been employed in the study of wide band gap materials. Ellipsometry is based on the study of changes in the polarization state of light upon reflection on a surface. READ MORE

  5. 3. Low Band-Gap Conjugated Polymers for Plastic Solar Cells

    Author : Erik Per Perzon; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; low band-gap conjugated polymers; Plastic solar cells;

    Abstract : Today, fossil fuels like coal, oil, and natural gas are used for more than 60% of the world's electricity production. These fuels have a very negative impact on the environment and many researchers agree that the earth's climate is changing as a consequence of fossil fuel emissions. READ MORE

  6. 4. Magnetism in Band Gap Engineered Sputtered MgxZn(1-x)O Thin Films

    Author : Sreekanth Mahadeva; K Venkat Rao; Lyubov Belova; Mark Fox; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Magnetron co-sputtering; MgO; MgxZn 1-x O; MnxMg 1-x O; thin films; Room-temperature ferromagnetism; band gap engineering; and intrinsic defects;

    Abstract : This dissertation presents a comprehensive study of the intrinsic room temperature ferromagnetism, RTFM, in technologically important thin films of ZnO, MgO, Mg@ZnO, the so-called d0–magnets that do not contain any intrinsic magnetic elements. We also present the first report on magnetism in Mn doped MgO films fabricated by dc magnetron sputtering. READ MORE

  7. 5. Technology and properties of InP-based photonic crystal structures and devices

    Author : Naeem Shahid; Srinivasan Anand; Rob W. vad der Heijden; KTH; []
    Keywords : Integrated optics materials; Photonic crystals; Planar waveguides; Dispersion; Band-gap; Mode-gap; mini-stopband; InP; Nanostructure fabrication; dry etching; mass transport; material reflow; reliability; SRA - ICT; SRA - Informations- och kommunikationsteknik;

    Abstract : Photonic crystals (PhCs) are periodic dielectric structures that exhibit a photonic band gap; a range of wavelengths for which light propagation is forbidden. 2D PhCs exhibit most of the properties as their three dimension counterparts with a compatibility with standard semiconductor processing techniques such as epitaxial growth, electron beam lithography, Plasma deposition/etching and electromechanical lapping/polishing. READ MORE