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Coming dissertations at Uppsala university

  • Order and interfaces in epitaxial heterostructures : Structure and magnetism Author: Anna L. Ravensburg Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-520686 Publication date: 2024-02-07 14:34

    The work in this dissertation is devoted to investigating order and interfaces in epitaxial heterostructures. To achieve that the software tool box GenL was developed for simulating and fitting x-ray diffraction patterns from epitaxial thin films, which is used to access structural information on the length scales of interfaces and atomic bonds. Employing GenL, it is shown that a small lattice mismatch between substrate and epitaxial layer is not the sole origin of high crystal quality, as demonstrated for nearly strain-free epitaxial growth of tungsten on sapphire with a lattice mismatch of up to 19.4 %. Furthermore, it is discussed that electronic states at the substrate/film interface can have substantial significance for the crystal structure of an epitaxial layer. For instance, despite a nearly mismatch-free interface of body-centered cubic iron on spinel, the presence of a boundary-induced interface layer with tetragonally distorted crystal structure is discovered, which has a profound impact on the magnetic properties. Finally, when creating multilayered structures, not only the interface states but the total structure is found to influence the physical properties, which is demonstrated for the interlayer exchange coupling in [Fe/MgO]N superlattices.

  • Hybrid Mismatches in International Transactions : A Study of Linking Rules in EU and Tax Treaty Law Author: Autilia Arfwidsson Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-519397 Publication date: 2024-02-07 14:18

    Hybrid mismatches, where differences in income characterisation across jurisdictions lead to double non-taxation, can be exploited by multinational enterprises to reduce their overall tax burden. Common hybrid mismatch rules addressing this issue have recently been introduced within the EU and the OECD. The adoption of these rules is unprecedented and poses a novelty for many states’ national tax systems. Beyond being technically complex, the operation of these rules necessitates interactions with other anti-avoidance rules, tax treaty provisions, EU law, OECD guidelines, and national rules in foreign jurisdictions.

    This thesis makes a significant contribution through its extensive structural examination of hybrid mismatches and their rules, covering both EU and tax treaty law. The examination primarily focuses on the hybrid mismatch rules in EU secondary law and their interactions with other aspects of EU and tax treaty law in preventing such mismatches. The analysis is conducted within the context of the rules’ underlying objectives.

    The study highlights five formal objectives of the rules: preventing tax avoidance, neutrality, equity, administrability, and legal certainty. However, a critical examination reveals that these objectives often lack substance or resemble political slogans. Several structural premises contributing to the occurrence of hybrid mismatches are identified, including the general trend of reducing or eliminating withholding taxes within EU and tax treaty law. While the hybrid mismatch rules play a crucial role in preventing mismatches, their complex design and technical limitations render them vulnerable to circumvention. Another issue is that they often risk resulting in unresolved double taxation when interacting with other parts of EU and tax treaty law. Ultimately, the rules are primarily focused on preventing tax avoidance but tend to overlook other objectives. The study particularly advocates for improved administrability and legal certainty.

  • Bias-adjusted analysis of global natural disaster records and an assessment of seismic hazard in Sweden Author: Niranjan Joshi Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-517257 Publication date: 2024-02-07 13:15

    Natural disasters pose significant challenges today and demand efficient allocation of society’s limited resources for disaster risk reduction. This relies on analysis of natural disaster records, which are prone to (reporting) biases that can affect the inferences drawn from their analysis. Data incompleteness is common in earthquake seismology, and, with a starting point in the Gutenberg-Richter law, this thesis studies the power-law behaviour between fatalities and the frequency of global natural disasters recorded by EM-DAT from 1900 to 2020. 

    Analysing, first, the power-law behaviour of global earthquake frequency and magnitude reveals overlapping patterns, and apparent improved reporting completeness over the studied periods, implying any increase in recorded earthquakes is a reporting artefact. Similarly, “frequency-magnitude” analysis of earthquake disasters shows power-law behaviour and an almost-unchanged distribution of fatalities over time, which also implies improved reporting. Similar analysis of hydro-meteorological disasters in EM-DAT shows their substantially increased number with time to be a reporting artefact driven by improved reporting of low-fatality disasters. The increasing gradient of the power-law part of the frequency-magnitude graphs implies that the worst events have become less fatal on average.  

    Climate-related disaster risk reduction actions have thus been very successful, resulting in a continuous decline in aggregate associated fatalities, to the extent that earthquakes have been the most fatal natural disasters over the last few decades.  Notably, while the earthquake magnitude distribution is dominated by earthquakes in high-seismicity zones, fatalities predominantly occur in low-seismicity intraplate regions. This implies that seismic hazard in Sweden, an intraplate area, may be significant, especially as earthquakes as large as M8 have occurred in its recent deglaciation phase. Hazard analysis based on data from the recently expanded Swedish seismic network clearly unveils significant hazard posed by Post-Glacial faults in the North. 

    This research advances our understanding of natural disaster dynamics, emphasizing the necessity for non-conventional methodologies to analyze historical data. It offers important insights to help form effective disaster risk reduction strategies, particularly in the context of seismic hazard assessment for specific regions like Sweden.

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