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The hydrodynamics and heat transfer in a reactor with a fluidized bed of catalyst particles and an inert material were simulated. The particle bed (the particle density was 2350 kg/m3, and the particle diameter was 1.5 to 4 mm) was located in a distribution device which was a grid of 90 × 90 × 60 mm vertical baffles. The behavior of the liquefying medium (air) was modeled using a realizable k-ε turbulence model. The behavior of particles was modeled using the discrete element method (DEM). In order to reduce the slugging effect, the particles were divided into four separate horizontal layers. It was determined that with the velocity of the liquefying medium close to the minimum fluidization velocity (1 m/s), slugging fluidization is observed. At a velocity of the liquefying medium of 3 m/s, turbulent fluidization in the lowest particle layer and bubbling fluidization on subsequent particle layers are observed. With an increase in the velocity of the liquefying medium over 3 m/s, entrainment of particles is observed. It was shown that a decrease in the density of the liquefying medium from 1.205 kg/m3 to 0.383 kg/m3 when it is heated from 298 K to 923 K would not significantly affect the hydraulic resistance of the bed. Based on the obtained results, it can be stated that the obtained model is optimal for such problems and is suitable for the further description of experimental data. [ABSTRACT FROM AUTHOR]

Despite the significant success of the human population in the development of the planet's resources, man will most likely never be able to completely get rid of dependence on the material and energy mechanisms of the biosphere. The clearest proof of this is the existence of urban ecosystems, within which human living space is formed. However, there is no consensus among researchers on the participation of social and natural components in the formation of urban ecosystems. Moreover, there is no clear answer to the question of how and through what mechanisms the space of human life is formed in modern cities. The article analyzes the ontological affiliation of the category "living space". Numerous aspects of the formation of modern living space have been studied on the specific examples of urban ecosystems of Kryvyi Rih and Uman. In particular, sample surveys of residents of these cities were conducted, based on the results of which conclusions are made about the quality of living space. Tourist activity and tourist resources are considered by the authors as a field of harmonization of human-environment relations in modern conditions of formation of living space.

The geographical, ecological and territorial peculiarities of the dynamics and the appearance’s reasons of the population’s sick rate in dependence on the environment’s state of Kryvyi Rih town with the aim of the stable development’s provision of the industrial regions. The influence of the contamination’s sources on the health state of the Kryvyi Rih population is cleared up and the space-time peculiarities of the sick rate’s display are established: the influence of the environmental risks’ factors on the population’s sick rate and the display of the diseases’ separate groups are defined, estimated and mapped, the spreading’s indicators of the ecologically dependent pathology from the distance to the stationary sources of pollution and from the factors of the environmental risks are revealed. The statistical base is created and the factors’ analysis of the environmental risks, the sick rate, the main demographical indicators of Kryvyi Rih population for the period of 2004 – 2019 is made and it’s determined that the sick rate and the mortality, caused by it, play the essential role in the development of the demographical situation of Kryvyi Rih town.

Technogenic tourism, as a relatively young trend in tourism, begins to play a significant role in Kryvbas, one of the oldest industrial regions in Ukraine. It has preserved the industrial heritage of the previous industrial and technological structure. Considering the considerable length and the total area of Kryvbas, classical methods of spatial research, in particular, the model of spatial optimization of access areas of Thiessen-Voronoi, can be effectively applied to studying, in particular, its tourist resources. In our case, 48 points that correspond to certain tourist attractions form a network with different levels of transport access. The basis was the digital map of Kryvbas, made in MapInfoProf environment in previous author's works. Next, with the special option of MapInfoProf, Voronoi polygons were developed which became the tool for further spatial analysis. Actually, the results of such analysis allowed to clarify the recreational and technogenic zoning of Kryvbas, as well as to study main laws of spatial organization of tourist attraction network of the region. Peculiarities of the modern spatial organization of tourist attraction network of Kryvorizhzhia encourage the conclusion on the presence of two major regions of the development of technogenic tourism within Kryvyi Rig. The first region is more developed Central-Southern with higher density and smaller average area of Voronoi polygons. The second one is the Northern with smaller number and larger average area of Voronoi polygons, as well as one that is more promising for the development of technogenic tourism. The results of the study will be useful in planning routes for tourist logistics. [ABSTRACT FROM AUTHOR]

Aiming to control by stress birefringence the radiotransparent fiber-glass plastic products based on highly cross-linked polymer matrices, theoretical regularities for mathematical description of this property were developed. Computer physical modeling of topological structure of experimental objects was carried out on epoxy-amine polymers with different cross-link density taken as an example. And constants of this model were specified. The adequacy of the model was demonstrated by comparison of the model-calculated against experimental approach to thermal polarization curves. [ABSTRACT FROM AUTHOR]