NATO military interventions in Kosovo, Libya, Afghanistan and their impact on relations with Russia after the Cold War

This thesis seeks to find out how NATO military interventions in Kosovo, Libya and Afghanistan have negatively affected relations with Russia. In order to achieve the aim and hypothesis of the study, the critical geopolitical approach is chosen as a theoretical framework.;The schematic critical geopolitics conceptualization of Gearoid O. Tuathail is used as the method of research. This thesis mostly pays attention to three essential parts of the critical geopolitics: formal geopolitics (analyses of think tanks, specialists, etc.), practical geopolitics (the decisions of policy makers, official statements, documents, strategies and speeches) and popular geopolitics (media discourse and opinion surveys). The combination of these three elements allows for a determination of certain NATO and Russian geopolitical discourses towards crises in Kosovo, Libya and Afghanistan. In relation to these crises, NATO and Russian geopolitical discourses are assessed from very positive, positive, neutral, to negative and very negative. This approach provides an opportunity to see how both sides have scripted these crises and how over the long term NATO\u27s military interventions in Kosovo, Libya and Afghanistan have influenced relations with Russia and affected the international order.;Moreover, descriptive method, discourse analysis and a comparative approach are used to scrutinize Russian and NATO\u27s geopolitical discourses towards crises. The analyses of NATO and Russian geopolitical discourses show the hypothesis that different NATO and Russian geopolitical discourses towards crises in Kosovo, Libya and Afghanistan have led to reciprocal accruing disagreements is only partly correct. The crisis of Kosovo in 2008 marked the end of the Russian flexible policy towards NATO and a new beginning of a permanently hostile geopolitical discourse against NATO in Europe. NATO military interventions in Kosovo, Libya and Afghanistan have negatively affected relations with Russia, mostly in Europe. Mutual cooperation and diplomatic disputes towards crises in Libya and Afghanistan are of minor importance in comparison with NATO-Russian relations on the European continent. Consequently, Russia concentrates most of its geopolitical attention towards Europe

Defektu elektroniskās struktūras noteikšana ar EPR optiskās detekcijas metodēm izolatoru materiālos

Publikāciju kopa un kopsavilkum

Optical detection of paramagnetic centres: from crystals to glass-ceramics

An unambiguous attribution of the absorption spectra to definite paramagnetic centres identified by the EPR techniques in the most cases is problematic. This problem may be solved by applying of a direct measurement techniques—the EPR detected via the magnetic circular dichroism, or briefly MCD–EPR. The present survey reports on the advantages and disadvantages applying the MCD–EPR techniques to simple and complex paramagnetic centres in crystals as well as glasses and glass-ceramics

Eu3+ ion distribution in oxyfluoride glass nanocomposites

The authors are grateful to Dr. Andris Fedotovs for photography of the samples. This research is funded by the Latvian Council of Science, project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1-0335.Assessment of activator distribution in lanthanide doped nanocomposites is an important and challenging task. Oxyfluoride glass ceramics have been chosen as a model system to characterize incorporation efficiency of Eu3+ ions in CaF2 nanocrystals using a combination of X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) techniques. Lattice constant changes induced by size mismatch of Eu3+ and Ca2+ ions have been used to evaluate Eu3+ content in CaF2. The distortion of CaF2 lattice due to incorporation of europium ions can be detected from EPR investigations via Gd3+ paramagnetic probe spectra. It is shown that ratio of different symmetry CaF2:Gd3+ centres and linewidth of EPR transitions can be used to monitor europium content in the crystalline phase of glass ceramics. ---- / / / ---- This is the preprint version of the following article: A. Antuzevics, G. Krieke, E. Pavlovska, U. Rogulis, Eu3+ ion distribution in oxyfluoride glass nanocomposites, Journal of Non-Crystalline Solids, 522, 119548 (2019), DOI https://doi.org/10.1016/j.jnoncrysol.2019.119548, which has been published in final form at https://www.sciencedirect.com/science/article/abs/pii/S0022309319304193. This article may be used for non-commercial purposes in accordance with Elsevier Terms and Conditions for Sharing and Self-Archiving. This work is licensed under a CC BY-NC-ND 4.0 license.Latvian Council of Science LZP-2018/1-0335; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4

The authors wish to express gratitude to K. Smits for TEM measurements. This research is funded by the Latvian Council of Science, project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1-0335. GK wishes to expresses gratitude to Arnis Riekstins "MikroTik" donation. Donations are administered by the University of Latvia Foundation. © 2019. This work is licensed under a CC BY-NC-ND 4.0 license.Transparent oxyfluoride glass ceramics containing hexagonal NaErF4 nanocrystals were synthesized by a heat treatment of a precursor glass obtained by the melt quenching technique. Combined X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis revealed the formation of single phase nanocrystals in the glass ceramics. The enhancement of intensity and spectral change of upconversion luminescence (UCL) confirmed the presence of Er3+ ions in the crystalline phase of the glass ceramics. Dominant energy transfer processes were identified using the rate equation formalism. Time-resolved site-selective spectroscopy studies at low temperatures were employed to elucidate the local structure of Er3+ ions in the glass ceramics and microcrystalline NaErF4. The origin of multi-site formation in hexagonal NaErF4 lattice is discussed.----/ / /---- This is the preprint of the following article: Guna Krieke; Andris Antuzevics, Maris Springis, Uldis Rogulis, Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4, Journal of Alloys and Compounds Volume 798 (2019), which has been published at https://www.sciencedirect.com/science/article/abs/pii/S0925346717304731. This article may be used for non-commercial purposes in accordance with Elsevier Terms and Conditions for Sharing and Self-Archiving. © 2019. This work is licensed under a CC BY-NC-ND 4.0 license.Latvian Council of Science LZP-2018/1-0335; University of Latvia Foundation; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

Optical detection of paramagnetic centres in activated oxyfluoride glass-ceramics

Electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD) and EPR detected via MCD (MCD-EPR) investigations have been performed on rare-earth activated oxyfluoride glasses and glass-ceramics. Er3+, Gd3+, and Mn2+ activators in oxyfluoride glass-ceramics show paramagnetic MCD behaviour and the MCD-EPR has been detected. The results of the MCD-EPR measurements for the Er-doped oxyfluoride glass-ceramics showed that Er3+ ions in the CaF2 crystallites in these ceramics embed only in the cubic symmetry environment, similarly to the previous observations of cubic Gd3+ centres in the glass-ceramics containing CaF2. Finally, the correlation of optics and paramagnetic centres is discussed for Mn-doped YAlO3 ceramics.Latvian-Ukrainian Joint Research Project (No LV-UA/2016/1 in Latvia and No M/78-2016 in Ukraine); Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Recombination luminescence of X-ray induced paramagnetic defects in BaY2F8

This research is funded by the Latvian Council of Science , project “Novel transparent nanocomposite oxyfluoride materials for optical applications”, project No. LZP-2018/1–0335 . The crystal growth research was funded by the CNPq (Brazil), project NO 421581/2016–6 .Recombination luminescence (RL) and RL-detected electron paramagnetic resonance (RL-EPR) in BaY2F8 single crystal has been investigated after irradiation with X-rays at low temperature. The recombination process, which lasts for several hours at 4 K, results in several broad bands in the RL spectrum. RL-EPR spectra show pronounced angular dependences on crystal orientation relative to external magnetic field. Based on the determined spin-Hamiltonian parameter values the recombination centres have been proposed to be F-type electron and self-trapped hole (VK) centresLatvian Council of Science LZP-2018/1–0335; CNPq 421581/2016–6; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Shortwave Ultraviolet Persistent Luminescence of Sr2MgSi2O7: Pr3+

This research is funded by the Latvian Council of Science, project “Defect engineering of novel UV–C persistent phosphor materials”, Project no. lzp-2021/1-0118. Institute of Solid State Physics, University of Latvia, as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.Currently, extensive research activities are devoted to developing persistent phosphors which extend beyond the visible range. In some emerging applications, long-lasting emission of high-energy photons is required; however, suitable materials for the shortwave ultraviolet (UV–C) band are extremely limited. This study reports a novel Sr2MgSi2O7 phosphor doped with Pr3+ ions, which exhibits UV–C persistent luminescence with maximum intensity at 243 nm. The solubility of Pr3+ in the matrix is analysed by X-ray diffraction (XRD) and optimal activator concentration is determined. Optical and structural properties are characterised by photoluminescence (PL), thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) spectroscopy techniques. The obtained results expand the class of UV–C persistent phosphors and provide novel insights into the mechanisms of persistent luminescence. © 2023 by the authors.--//-- This is an open access article Antuzevics A., Doke G., Krieke G., Rodionovs P., Nilova D., Cirulis J., Fedotovs A., Rogulis U.; Shortwave Ultraviolet Persistent Luminescence of Sr2MgSi2O7: Pr3+ (2023) Materials, 16 (5), art. no. 1776; DOI: 10.3390/ma16051776; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85149833044&doi=10.3390%2fma16051776&partnerID=40&md5=03c546fb3fc6c7d6c16d4d482b4038ca published under the CC BY 4.0 licence.Latvian Council of Science, Project no. lzp-2021/1-0118; Institute of Solid State Physics, University of Latvia, as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2