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In this article, the mechanism of relaxation polarization currents occurring at a constant temperature (isothermal process) in crystals with ionic-molecular chemical bonds (CIMBs) in an alternating electric field was investigated. Methods of the quasi-classical kinetic theory of dielectric relaxation, based on solutions of the nonlinear system of Fokker–Planck and Poisson equations (for the blocking electrode model) and perturbation theory (by expanding into an infinite series in powers of a dimensionless small parameter) were used. Generalized nonlinear mathematical expressions for calculating the complex amplitudes of relaxation modes of the volume-charge distribution of the main charge carriers (ions, protons, water molecules, etc.) were obtained. On this basis, formulas for the current density of relaxation polarization (for transient processes in a dielectric) in the k-th approximation of perturbation theory were constructed. The isothermal polarization currents are investigated in detail in the first four approximations (k = 1, 2, 3, 4) of perturbation theory. These expressions will be applied in the future to compare the results of theory and experiment, in analytical studies of the kinetics of isothermal ion-relaxation (in crystals with hydrogen bonds (HBC), proton-relaxation) polarization and in calculating the parameters of relaxers (molecular characteristics of charge carriers and crystal lattice parameters) in a wide range of field parameters (0.1–1000 MV/m) and temperatures (1–1550 K). Asymptotic (far from transient processes) recurrent formulas are constructed for complex amplitudes of relaxation modes and for the polarization current density in an arbitrary approximation k of perturbation theory with a multiplicity r by the polarizing field (a multiple of the fundamental frequency of the field). The high degree of reliability of the theoretical results obtained is justified by the complete agreement of the equations of the mathematical model for transient and stationary processes in the system with a harmonic external disturbance. This work is of a theoretical nature and is focused on the construction and analysis of nonlinear properties of a physical and mathematical model of isothermal ion-relaxation polarization in CIMB crystals under various parameters of electrical and temperature effects. The theoretical foundations for research (construction of equations and working formulas, algorithms, and computer programs for numerical calculations) of nonlinear kinetic phenomena during thermally stimulated relaxation polarization have been laid. This allows, with a higher degree of resolution of measuring instruments, to reveal the physical mechanisms of dielectric relaxation and conductivity and to calculate the parameters of a wide class of relaxators in dielectrics in a wide experimental temperature range (25–550 K).

The rapid and significant expansion of urban areas is observed worldwide; however, considerable differences are detected within the characteristics of the process. The rural–urban fringe is changing most dynamically from the aspect of land use and this tends to be relevant in the case of post-socialist cities in Central Europe even with a stagnating or decreasing population. Debrecen (Hungary) and its hinterland adequately represent the migration trends of Hungarian cities and the great administrative area provided wide intra-urban suburbanization processes. The current study put the emphasis on the analysis of the spatial pattern of built-up areas and the distribution of residents. In order to discover the processes of the post-socialist transition period, detailed point layers were created to illustrate every built-up parcel in the rural–urban fringe of Debrecen (for the years 1980, 2000, and 2020). The most important characteristics were discovered with the help of GIS methods—Kernel-density, grid pattern analysis of the object density, and analysis of land cover/land use changes using Corine Land Cover Change (CLCC) databases. The dynamic and extended expansion of built-up areas was seen until 2000, in which the outskirts (including hobby gardens) densified spectacularly. The urban sprawl has been less intensive since the millennium and the increase in built-up areas has become more concentrated. As a consequence of the transition period, extended territories—primarily the least dense parts of the rural–urban fringe—are faced with the disappearance of buildings due to agricultural cultivation reasons.

Exploring the main cooperation schemes between the member-states of the Eurasian Economic Union (EAEU) within a broader context of the geopolitical processes in the Post-Soviet space, the article intends to discuss the feasibility of integration among Former Soviet countries. The article intends to present the formally announced integration initiatives in the Post-Soviet space (such as the CIS, EurAsEC and EAEU) as part of a de-facto ongoing process of disintegration that started right after the collapse of the Soviet Union. Within this scheme, Russia consistently acts as a generator of a centripetal integration force by proposing different institutional frameworks for integration. However, it is not sufficiently powerful to overcome the centrifugal inertia acquired by the rest of the Post-Soviet states. The article concludes that, in spite of its formal integration purposes, the EAEU is indeed another stage of the ongoing disintegration process in the Post-Soviet space.

The aim of the article is to examine one of the neglected areas in the spatiality of religion, the spatial distribution of religious institutions and the changes that have taken place in this relation over time in the case of Debrecen, a specific city in Hungary, which has hosted several religions both in the past and present. The main findings are discussed in five subsections concentrating on five consecutive periods. During the period under study, the number of institutions run by churches increased steadily until the Second World War. This process was interrupted after the Second World War, and partly as a consequence of the world war (with the deportation of Jews to concentration camps) and partly due to the anti-religious nature of the socialist regime, there was a significant decline followed by a resumption of expansion after 1990. Regarding the location of the institutions within the city and its changes, there were significant differences between the various types of institutions (e.g., churches, administrative centres, kindergartens, elementary and grammar schools). Research primarily relied on document analysis and fieldwork.