Iskanje po repozitoriju

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Opis: The Carniolan Savings Bank was the first financial institution in the Slovenian territory. It was founded in 1820 in Ljubljana, the capital city of Carniola, a province in the Austrian part of the Habsburg Monarchy. This institution collected deposits and managed the credit operations in the country. Even after the basic idea changed due to business development, it continued to play a significant role as a microfinance provider. The thesis covers the period from the establishment of the institution in 1820 to the disintegration of the Austro-Hungarian Monarchy in 1918. Therefore, the study also deals with the main features of the interwar period. It draws attention to some issues faced by the Savings Bank between 1918 and 1945. The dissertation defines the importance and dimensions of innovation in the institutional sense that the Savings Bank acquired. It defines the role that the institution had in an economic, social, political and national context. This has been achieved through in-depth analysis and a classic historical approach. The dissertation provides an original study of the extensive and unexplored historical material. The Carniolan Savings Bank provides an excellent example of the intertwining of politics and nationalism with economic development. It had a significant impact on the changes that were a prerequisite for mobilising the financial resources of social classes that previously had no access to banking services. Therefore, the Savings Bank collected dispersed financial resources on the financial market by allocating capital to various investment opportunities. The most prominent were mortgage loans and the purchase of government securities. However, the rules in place at the state level limited the importance of the Savings Bank to the regional and especially the local level, reflecting its impact on the country’s economic development. Accordingly, it sought ways to get involved, as evidenced by Credit Association that was used by small merchants and craftsmen.
Ključne besede: Carniolan Savings Bank, deposits, credit activity, microfinance, investments, economic nationalism, Habsburg Monarchy, the Province of Carniola
Objavljeno v RUNG: 06.01.2022; Ogledov: 2121; Prenosov: 159
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Opis: A unique material, ceria (CeO2), which is widely applied in automobile exhaust catalysts, is functional due to presence of defects in its crystal structure. Furthermore, the structural defects dictate electrical and chemical properties of ceria. The creation of intrinsic oxygen vacancies in ceria is responsible for oxygen-ion conductivity in solid oxide fuel cells. This unfolds the keen interest in ceria defects. Using the analytical technique cathodoluminescence spectroscopy (CLS) we can characterize ceria for its band gap and the defect states within the band gap. Since CLS has a high spatial resolution, high sensitivity to low concentration of defects and ability to obtain depth resolved information it is an obvious technique of choice. The first part of the thesis is an introduction to the topic and description of the experimental techniques. Importance of ceria as a multifaceted material finding applications in areas spanning from energy production and conversion to biomedical applications is detailed. CLS as a tool to understand defect-related optical properties and advancement in the CL detection systems are discussed. To study the relationship between local structure and its impact on CL emission spectra, an X-ray absorption spectroscopy techniques were used. The X-ray absorption near edge structure (XANES) and the Extended x-ray absorption fine structure (EXAFS) techniques are summarized. The second part discusses CL emission from ceria. Initially, CL emission from reduced ceria and its dependence on oxygen vacancy concentration are presented. The origin of emission was attributed to different configurations of the oxygen vacancies and polarons. The recent F center description in ceria was adopted here. The intriguing observation of CL emission quenching as a function of oxygen vacancy concentration was explained on the basis of a relative change in population of F centers in ceria. This demonstrated the relevance of local structure for the CL emission in ceria. In order to have a better understanding of the system, La-doped ceria was proposed as a model system. A precise control over the stoichiometry helped to achieve a desired oxygen vacancy concentration. The CL emission behavior, as observed in reduced ceria, was replicated in the case of La-doped ceria and the analysis revealed that F+ centers favor CL emission whereas F0 centers are disadvantageous. The local structure investigation using EXAFS analysis of both cations Ce and La (K-Edge) showed distortion from the fluorite symmetry and corroborated the F center description of oxygen vacancies in ceria. Our results provide an experimental evidence for F center description involving oxygen vacancies and polarons.
Ključne besede: ceria, cathodoluminescence spectroscopy, local structure distortion, EXAFS analysis, La doped ceria, luminescence quenching, F centers, dissertations
Objavljeno v RUNG: 25.11.2021; Ogledov: 2419; Prenosov: 104
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Opis: Knowing the geological evolution of Earth surface allows identifying various natural attractions (biotic and abiotic). It makes possible the use of the most differentiated resources for the practice of tourism. The Arcos-Pains Karst Region has excellent potential for geotourism use. Examples of geosites include the Santuario and Brega Caves, the Dry Valley in the Corumbá region, and the Mastodonte Cave, where fossils of the Haplomastodon waringi mastodon species were found. However, public investment policies aiming at the environmental preservation of this heritage are still minimal or absent. The region also suffers tremendous anthropic pressure due to the extraction and processing of limestone, agribusiness, urban expansion and informal tourism. The process of inventorying and quantifying geosites is an essential tool for defining geoconservation strategies since it is not possible to protect all the geodiversity of the planet. The attributes analysed should integrate several criteria that take into account the intrinsic characteristics of each geosite, its potential use and the level of protection required. Regarding this research, the objective is approaching karst and speleological heritage, intending to define geosites for scientific, educational and tourist use at the Arcos-Pains Karst Region. The purpose of the inventory is to develop a geotourism project that provides essential information for better territorial management. It is also intended to assist environmental agencies in the enterprises’ environmental licensing processes installed in the region. Among the thirty-five (35) sites evaluated, eleven (11) presented above-average use-values in all categories analysed. Also, they presented national relevance and were classified as geosites. In addition to these, another sixteen (16) sites scored sufficiently to be categorised with national relevance. Within the geosites, one (1) was of international relevance: the São Francisco River Canyon. Considering the results, it is essential to deepen the research regarding karst dynamics to equalise geodiversity preservation while allowing its use to benefit society.
Ključne besede: Geodiversity, Geotourism, Geosites, Arcos-Pains Karst Region, Karst, Speleology
Objavljeno v RUNG: 22.10.2021; Ogledov: 2374; Prenosov: 164
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Opis: Topological insulators (TIs) represent a new state of matter that possess a different band structure than regular insulators or conductors. They are characterized with a band gap in the bulk and conductive topological states on the surface, which are spin polarized and robust toward contamination or deformation of the surface. Since the intriguing properties of the TIs are localized at the surface, it is important to obtain knowledge of the possible phenomena happening at the interface between TIs and other materials. This is especially true in the case of metals, due to the fact that such interfaces will be present in the majority of foreseen TI applications. The presented study combines microscopy and spectroscopy techniques for characterization of morphology, stability and chemical interaction at the interface between TI and metals deposited by means of physical vapor deposition. Our research is based on the interface of Bi2Se3 topological insulator with Ag, Ti and Pt – metals that can be encountered in devices or applications predicted to utilize the special properties of topological insulators. STM and SEM imaging of Ag/Bi2Se3 interface showed that Ag atoms arrange on the surface in the form of islands, whereas significantly bigger agglomerates are found at the surface steps. The interface was found to be unstable in time and resulted in the absorption of the metal into the crystal at room temperature. Evidences of a chemical reaction at the Ag/Bi2Se3 interface are presented, showing that new phases (Ag2Se, AgBiSe2 and metallic Bi) are formed. Deposition of Ti on Bi2Se3 resulted in different morphologies depending on the film thickness. At a very low coverage (<1 Å) islands are formed. However, the islands growth is hindered before the completion of a full layer due to the occurrence of a chemical reaction. No surface features could be detected by SEM for Ti coverage up to 20 nm. In contrary, when Ti thickness reached 40 nm, compressive stress triggered buckling of the deposited film. XPS analysis revealed that a redox solid-state reaction occurs at the Ti/Bi2Se3 interface at room temperature forming titanium selenides and metallic Bi. The reaction has significant kinetics even at cryogenic temperature of 130 K. Pt forms a homogenous film over the whole substrate surface, which is stable in time at room temperature. Although the interface of Pt with Bi2Se3 was found to be i less reactive compared to Ag and Ti, an interfacial phase formed upon annealing to ∼90 °C was detected by TEM cross section experiment. A model for prediction of interfacial reactions between a metal and Bi2Se3 based on the standard reduction potential of the metals and Gibbs free energy for a model reaction is presented. Based on these two values the reaction can be expected to result in the formation of binary and/or ternary selenides and Bi. Presented work shows on the importance of metal/topological insulator interfaces characterization taking into account the possibility of a chemical reaction with all of its consequences. Results should be considered for future theoretical and applicative studies involving such interfaces as well as for the possible engineering of 2D TI heterostructures.
Ključne besede: topological insulators, topological surface states, Bi2Se3, thin films, Ag, Ti, Pt, morphology, interfaces, solid-state reaction, metal selenides, reactivity, stability, electron microscopy, dissertations
Objavljeno v RUNG: 09.06.2021; Ogledov: 3645; Prenosov: 173
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Opis: The main aim of the dissertation is to develop a novel numerical approach for an accurate and computationally efficient modelling of dendritic solidification, which is one of the most commonly observed phenomena in the industrial casting of the metallic alloys. The size and the morphology of dendritic structures as well as the distribution of the solute within them critically effect the mechanical and the electro-chemical properties of the solidified material. The numerical modelling of dendritic solidification can be applied for an in-depth understanding and optimisation of the casting process under various solidification conditions and chemical compositions of the alloy under consideration. The dendritic solidification of pure materials and dilute multi-component alloys is considered in the dissertation. The phase field formulation is applied for the modelling of dendritic solidification. The formulation is based on the introduction of the continuous phase field variable that is constant in the bulk of the solid and liquid phases. The phase field variable has a smooth transition from the value denoting the solid phase to the value denoting the liquid phase at the solid-liquid interface over the characteristic interface thickness. A phase field model yields a system of coupled non-linear parabolic partial differential equations that govern the evolution of the phase field and other thermodynamic variables. The meshless radial basis function-generated finite-differences (RBF-FD) method is used for the spatial discretisation of the system of partial differential equations. The forward Euler scheme is applied for the temporal discretisation. Fifth-degree polyharmonic splines are used as the shape functions in the RBF-FD method. A second-order accurate RBF-FD method is achieved by augmenting the shape functions with monomials up to the second degree. The adaptive solution procedure is developed in order to speed-up the calculations. The procedure is based on the quadtree domain decomposition of a rectangular computational domain into rectangular computational sub-domains of different sizes. Each quadtree sub-domain has its own regular or scattered distribution of computational nodes in which the RBF-FD method and the forward Euler scheme apply for the discretisation of the system of partial differential equations. The adaptive solution procedure dynamically ensures the prescribed highest density of the computational nodes at the solid-liquid interface and the lowest-possible density in the bulk of the solid and liquid phases. The adaptive time-stepping is employed to further speed-up the calculations. The stable time step in the forward Euler scheme depends on the density of the computational nodes; hence, different time steps can be used in quadtree sub-domains with different node densities. The main originality of the present work is the use of the RBF-FD method for the thorough analysis of the impact of the type of the node distribution and the size of a local sub-domain to the accuracy when the phase field modelling of dendritic solidification for arbitrary preferential growth directions is considered. It is shown how the use of the scattered node distribution reduces the undesirable mesh-induced anisotropy effects, present when the partial differential equations are discretisied on a regular node distribution. The main advantage of the RBF-FD method for the phase field modelling of dendritic growth is the simple discretisation of the partial differential equations on the scattered node distributions. The RBF-FD method is, for the first time, used in combination with the spatial-temporal adaptive solution procedure based on the quadtree domain decomposition. The adaptive solution procedure successfully speeds-up the calculations; however, the advantages of the use of the scattered node distribution are partly compromised due to the impact of regularity in the quadtree domain decomposition.
Ključne besede: dendritic solidification, phase field method, meshless methods, RBF-FD, adaptive solution procedure
Objavljeno v RUNG: 07.04.2021; Ogledov: 2970; Prenosov: 134
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