Assessment of some parameters of biological quality of the water in the city of KropIvnytskyi

The aim of the work is to compare the biological buffer functions of aquatic ecosystems of the middle stream of the Dnipro river near the water intake and the Inhul river in Kropyvnytskyi

Half-metallicity and efficient spin injection in AlN/GaN:Cr (0001) heterostructure

First-principles investigations of the structural, electronic and magnetic properties of Cr-doped AlN/GaN (0001) heterostructures reveal that Cr segregates into the GaN region, that these interfaces retain their important half-metallic character and thus yield efficient (100 %) spin polarized injection from a ferromagnetic GaN:Cr electrode through an AlN tunnel barrier - whose height and width can be controlled by adjusting the Al concentration in the graded bandgap engineered Al(1-x)Ga(x)N (0001) layers.Comment: submitted for publicatio

Magnetically Mediated Transparent Conductors: In2_2O3_3 doped with Mo

First-principles band structure investigations of the electronic, optical and magnetic properties of Mo-doped In$_2$O$_3$ reveal the vital role of magnetic interactions in determining both the electrical conductivity and the Burstein-Moss shift which governs optical absorption. We demonstrate the advantages of the transition metal doping which results in smaller effective mass, larger fundamental band gap and better overall optical transmission in the visible -- as compared to commercial Sn-doped In$_2$O$_3$. Similar behavior is expected upon doping with other transition metals opening up an avenue for the family of efficient transparent conductors mediated by magnetic interactions

Environment quality management in green cities

The article is devoted to the issues of improvement of quality of urban environment during realization of the project of development of green cities, which combines economic and ecological advantages. The article substantiates top-priority directions of change of approaches to management of urban territories and integration of efforts of science, business, and society in promotion of green technologies. The main methodological approach to provision of ecological balance in green cities consists in development of the most comprehensive complex of ecological and economic indicators of development of the city in view of implementation of progressive technologies of filtration of industrial emissions into the atmosphere, sewage water treatment, waste processing, etc. The article offers methodological substantiation of the system of indicators which include evaluation of anthropogenic influence on urban environment and calculation of integrated economic effect from implementation of green technologies which minimize unfavorable effect of these influences. These indicators include emissions release into the atmosphere, soil pollution, development of green areas, use of urban territories which are taken out from the system of natural use, use of city public transport, etc. The developed indicators can not only reflect the existing ecological state and economic development of the city fully but be used for development of perspective scenarios of development of green urban economy on the basis of industrially developed middle-sized cities of Russia and the CIS.peer-reviewe

Concept - strategy “green cities” on the basis of medium industrially developed cities of Russia and CIS countries

The work is oriented at conceptual and methodological substantiation of the strategy of formation of “green cities” on the basis of medium industrially developed cities of Russia and post-Soviet countries, which provide new ecological and socio-economic standards of living standards of population. The concept of “green city” has not only to correspond to imperatives of competitiveness, sustainability, and security of economy, but to form mechanisms of creation of material and informational, humanitarian and technical, institutional and organizational, commercial and financial conditions for effective realization of potential of medium cities. In order to substantiate the results of the research, the following methods of scientific analysis were used: systemic, situational, historical and logical, typological; methods of structural & functional, subjective & objective, descriptive, comparative, expert, statistical, graphic, and table analysis, and economic & mathematical modeling. Study of the processes of transformation of socio-economic system of medium cities on the basis of developed institutional criteria allowed expanding methodological basis of strategic management – in particular, substantiating the totality of methodological and methodical decisions, related to conduct of the analysis, substantiation of goals and mission, development and realization of strategy. Analysis of external and internal possibilities and limitations of medium city development allows determining factors which influence its state and trajectory of development positively and negatively: organizational & managerial (dominant of local authorities’ focus at cooperation with regional and federal structures), technical and technological (orientation of vector of industry modernization), infrastructural (imperative of implementation of resource-saving technologies), ecological (recession of ecological culture of population), tourist and recreational (slowdown in development of recreational resources and creation of tourism industry), informational and communicational (priority of creation of “E-city”), and social (horizon of new social standards).peer-reviewe

Model of Economic Phenomenon

As is known, economic phenomena represent the most important part of the subject of economic science. However, modern economic theory avoids a clear definition of this category. Thus, it remains unclear what is economic phenomena, and thus the economy is in its essence as suc

Role of Coulomb correlation on magnetic and transport properties of doped manganites: La0.5Sr0.5MnO3 and LaSr2Mn2O7

Results of LSDA and LSDA+U calculations of the electronic structure and magnetic configurations of the 50% hole-doped pseudocubic perovskite La0.5Sr0.5MnO3 and double layered LaSr2Mn2O7 are presented. We demonstrate that the on-site Coulomb correlation (U) of Mn d electrons has a very different influence on the (i) band formations, (ii) magnetic ground states, (iii) interlayer exchange interactions, and (iv) anisotropy of the electrical transport in these two manganites. A possible reason why the LSDA failures in predicting observed magnetic and transport properties of the double layered compound - in contrast to the doped perovskite manganite - is considered on the basis of a p-d hybridization analysis.Comment: 11 pages, 3 figure

Communicative texts' modelling of engineering profiles as a methodological problem

The article presents methodological materials for teaching professional foreign language (Russian), which stimulate foreign students’ communicative competence in the sphere of educational and professional communication. The structure of texts in terms of their communicative purpose is analyzed and the subject of speech in the “fabric” of the text based on the example of texts in “General Electrical Engineering” is discussed. The proposed approach introduces international students to the particularities and traditions of the presentation of scientific and technical information adopted by Russian engineering schools as one factor in the development of language culture

Spatial Distribution and Magnetism in Poly-Cr-doped GaN from First Principles

Large scale density-functional theory calculations have been performed to understand the spatial distribution and magnetic coupling of Cr-doped GaN, in which exhaustive structural and magnetic configurations have been investigated by doping of up to five Cr atoms in large supercells. Our results provide direct evidence that the distribution of the doped magnetic ions is neither homogeneous nor random as widely assumed previously. Rather, under both Ga-rich and N-rich growth conditions, the Cr atoms have a strong tendency to form substitutional, embedded clusters with short-range magnetic interactions maintaining the wurtzite structure. Significantly, while the ferromagnetic state is favored for pair doping, for more than two-Cr-atom clustering configurations, states containing antiferromagnetic or ferrimagnetic coupling with net spins in the range of 0.06-1.47µB/Cr are preferred. The formation of embedded clusters leads to notable local structural distortions and considerable magnetic moments on the Cr-bonded N atoms. Also importantly, the electrical properties (metallic, half-metallic, or semiconducting) are found to strongly depend on the dopant concentration. We propose a picture where various cluster configurations coexist and the statistical distribution and associated magnetism depend sensitively on sample growth details. The results obtained are in agreement with recent experiments. Such a view can explain many hitherto puzzling experimental observations, e.g., the much lower value of the measured mean saturation magnetic moment on Cr as compared to the theoretically predicted value for the isolated dopants; the anomalous lattice constant change in relation to the dopant concentration and temperature; and the strong dependence of the magnetization on the Cr concentration, growth temperature, and annealing. We find a similar behavior for Mn in GaN and Cr and Mn in AlN and argue that such a scenario may also hold for other dilute magnetic semiconductor systems

Tendencies and prospects of tourism industry in Russia : sociological analysis of stereotypes among population during tourism trips

This article deals with the current problem – development of cultural and educational tourism industry. The information for the study was collected from the questionnaires of population of municipal districts of Russia, from the information provided by the Federal Service of State Statistics, and the results of the surveys conducted by the Russian Public Opinion Research Center (VCIOM), etc. In the course of the study, the authors revealed that the diverge social groups of the Russian society perceive Russian cultural and educational potential, tourism service in the cities in a different way; the tendencies and basic principles of domestic tourism industry have been revealed. In the article the authors defined direct dependence between weak developed domestic infrastructure and stagnation of domestic tourism industry. The results of the study showed the stereotypes which tourists follow while choosing destinations for their trips. These stereotypes may be divided into the following groups: price, comfort, climate. They range in different social groups that lead to the market fluctuation of the domestic tourism industry.peer-reviewe