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Using first-principles combined with quantum transport calculations, we predict that graphene sandwiched between insulating monolayers of Cr₂Ge₂Te₆ ferromagnet and WS₂ transition-metal dichalcogenide will exhibit spin-orbit torque (SOT) when unpolarized charge current is injected parallel to interfaces of Cr₂Ge₂Te₆/graphene/WS₂ van der Waals (vdW) heterostructure. Although graphene by itself is nonmagnetic and it has negligible spin-orbit coupling (SOC), both of which are required for the SOT phenomenon, Cr₂Ge₂Te₆ induces proximity magnetism into graphene while WS₂ concurrently imprints valley-Zeeman and Rashba SOCs in it. Unlike SOT on conventional metallic ferromagnets brought into contact with normal materials supplying strong SOC, the predicted SOT on such doubly proximitized graphene can be tuned by up to two orders of magnitude via combined top and back electrostatic gates. The vdW heterostructure also reveals how damping-like component of the SOT vector can arise purely from interfaces and, therefore, even in the absence of any spin Hall current from the bulk of a material with strong SOC. The SOT-driven dynamics of proximity magnetization moves it from out-of-plane to in-plane direction which opens a gap in graphene and leads to zero off current and diverging on/off ratio in such SOT field-effect transistor.

The recently discovered two-dimensional (2D) magnetic insulator CrI₃ is an intriguing case for basic research and spintronic applications since it is a ferromagnet in the bulk, but an antiferromagnet in bilayer form, with its magnetic ordering amenable to external manipulations. Using first-principles quantum transport approach, we predict that injecting unpolarized charge current parallel to the interface of bilayer-CrI₃/monolayer-TaSe₂ van der Waals heterostructure will induce spin-orbit torque (SOT) and thereby driven dynamics of magnetization on the first monolayer of CrI₃ in direct contact with TaSe₂. By combining calculated complex angular dependence of SOT with the Landau-Lifshitz-Gilbert equation for classical dynamics of magnetization, we demonstrate that current pulses can switch the direction of magnetization on the first monolayer to become parallel to that of the second monolayer, thereby converting CrI₃ from antiferromagnet to ferromagnet while not requiring any external magnetic field. We explain the mechanism of this reversible current-driven nonequilibrium phase transition by showing that first monolayer of CrI₃ carries current due to evanescent wavefunctions injected by metallic transition metal dichalcogenide TaSe₂, while concurrently acquiring strong spin-orbit coupling (SOC) via such proximity effect, whereas the second monolayer of CrI₃ remains insulating. The transition can be detected by passing vertical read current through the vdW heterostructure, encapsulated by bilayer of hexagonal boron nitride and sandwiched between graphite electrodes, where we find tunneling magnetoresistance of $\backslashsimeq 240$%.

In this thesis we use methodologies that are grounded on a ``bottom-up'' approach, denoting the importance of considering the emergence of the aggregate economic behavior from the interaction of heterogeneous economic agents. We apply this ``bottom-up' methodology both for designing a macroeconomic multi-country model and for studying the bank credit allocation in Spain from micro data about the balance sheet of Spanish companies. The work on the multi-country model allows us to examine the macroeconomic implications of joining a union for two countries in different economic scenarios. Our main conclusions are that the performance of the union is in general superior to the performance of isolated countries, but in some cases the union can exacerbate inequalities between the countries. In empirical work we discovered that large companies obtained most of the loans in Spain., En esta tesis utilizamos metodologías basadas en un enfoque "bottom-up", que denotan la importancia de considerar la formación del comportamiento económico agregado a partir de la interacción de los agentes económicos heterogéneos. Aplicamos esta metodología "bottom-up" tanto para el diseño de un modelo macroeconómico multinacional como para el estudio de la asignación de crédito bancario en España a partir de datos microeconómicos sobre el balance de las empresas españolas. El trabajo sobre el modelo multinacional nos permite examinar las implicaciones macroeconómicas de unirse en una unión para dos países en diferentes escenarios económicos. Nuestras principales conclusiones son que la performance de la unión es en general superior a la performance de los países aislados, pero en algunos casos la unión puede exacerbar las desigualdades entre los países. En el trabajo empírico descubrimos que las grandes empresas obtuvieron la mayor parte de los préstamos en España.

Understanding the movement of tourists within a destination and predicting future movements have their practical applications for destination management, product development, marketing and attraction. We analyzed the seasonality of tourist presence in Belgrade, using the ARIMA models, with the aim of predicting future movement. We came to the result that about three-fourths of tourists in this area consist of domestic tourists or residents of Belgrade and people from other parts of Serbia, while the rest are foreign tourists. By increasing the number of foreign tourists there would be a significant economic development both for Ada Ciganlija Island and for Belgrade. This also points to the need for improving marketing and significantly engaging and making this area closer to foreign tourists.

Tourist guides are in direct contact with the tourists on the group package tours. They play an important role in creating tourist experience and the perception of a destination and travel company. For that reason, the purpose of this study was to determine customers’ perceptions of service provided by tourist guides in group package tours which were organized by Serbian travel agencies. Research model used 16 items of service quality which were grouped into four dimensions. The paper provided results and indicated the items of tourist guide service quality that should be improved. Further, it was explored how the four service factors were related to reputation of travel agency and word-of-mouth marketing. The results of regression analysis showed that dimensions of service quality of tourist guides influence the reputation of a travel agency and word-of-mouth marketing, whereby the importance of tourist guides in group package tours was again confirmed., tourismos, Vol. 9 No. 1 (2014)

In this paper we will give an overview of the more relevant results on the theoretical and experimental research related to public and private information dissemination and aggregation in asset markets, focusing mainly on the contemporaneous presence of public and private information and its effect on market performance. We conclude that the theoretical literature is more developed than the experimental one when dealing with public information and its role in different economic environments. Therefore, a promising research avenue opens for experimentally testing the different, and often contradictory, theoretical results.

Tc-99m-methoxyisobutylisonitril (MIBI) scintigraphy is localizing diagnostic methods that is used for detection of sicken parathyroid gland (PT). The use of this method for PT diseases diagnosis makes surgical treatment of a patient more successful. This is a report about the patient who was surgically treated for primary hyperparathyroidism caused by hyperplasia of parathyroid glands and cancer of ectopic parathyroid gland. He was operated in two acts. The first surgical intervention was performed without preoperative diagnostics of Tc-99m-MIBI scintigraphy, while the second surgical intervention was preceded by Tc-99m-MIBI scintigraphy which clearly showed the existence of tumor in the back mediastinum (ectopic parathyroid gland). Pathophysiological analysis of the extirpated parathyroid gland showed the case of ectopic parathyroid gland cancer. The use of Tc-99m-MIBI scintigraphy as a localizing method before the first surgical intervention could have saved the patient from the second one and from risks it could have caused, as well.