Mechanism of mechanochemical synthesis of complex oxides and the peculiarities of their nano-structurization determining sintering

A mechanism of superfast mechanosynthesis reaction for oxide systems is proposed on the base of a dynamics study. The threshold effect and linear dependence of the chemical response on the effective temperature of the reaction zone are established. Major factors are determined: molecular mass of reagents, enthalpy and difference of reagents in Mohs’s hardness, which also influence the composition of the primary product. Primary acts are characterized by a superfast roller mechanism of mass transfer with the formation of a transient dynamic state (D)*. Secondary acts slowly approximate the composition of the product to the composition of the starting mixture by diffusion mass transfer in a deformation mixing regime with a contribution of a rotation (roller) mechanism. The list of structure types for complex oxides derived by mechanosynthesis includes perovskites, fluorites, pyrochlors, sheelites, and some other ones. Powders of crystal products display multilevel structurization. In all studied complex oxides strong disordering of the “anti-glass” type was observed. The mechanism of sintering was studied in BaTiO3 powders of different origin and in metastable complex oxides derived by mechanosynthesis. The major contribution in shrinkage belongs to rearrangements of crystalline particles as a whole. Structure transformations accompany, as a rule, sintering of inhomogeneous powders derived by mechanosynthesis

Palynological Investigations of Miocene Deposits on the New Siberian Archipelago (U.S.S.R.)

New paleobotanical data (mainly palynological) are reported from Miocene beds of the New Siberian Islands. The palynoflora has a number of distinctive features: the presence of typical hypoarctic forms, the high content taxa representing dark coniferous assemblages and the considerable proportion of small-leaved forms. Floristic comparison with the paleofloras or the Beaufort Formation in arctic Canada allows interpretation of the evolution of the Arctic as a landscape region during Miocene-Pliocene time. The paper is a preliminary analysis of the mechanisms of arctic florogenesis. The model of an "adaptive landscape" is considered in relation to the active eustatic drying of polar shelves.Key words: palynology, U.S.S.R., New Siberian Islands, Miocene, Arctic, florogenesisRÉSUMÉ. On rapporte de nouvelles données paléobotaniques (principalement palynologiques) venant de couches datant du miocène situées dans l’archipel de la Nouvelle-Sibérie. La palynoflore possède un nombre de caractéristiques particulières, parmi lesquelles, la présence de formes hypoarctiques typiques, la grande quantité de taxons représentant des assemblages de conifires sombres, ainsi qu’une collection considérable de formes à petites feuilles. Une comparaison floristique avec les paléoflores de la formation de Beaufort dans l’Arctique canadien permet d’interpréter l’évolution de l’Arctique en tant que zone peuplée d’espèces végetales durant le miocène et le pliocène. Cet article est une analyse préliminaire des mécanismes de la genèse de la flore arctique. Le modèle d’un paysage adaptatif est envisagé en rapport avec l’assèchement eustatique actif des plates-formes polaires.Mots clés: palynologie, U.R.S.S, archipel de la Nouvelle-Sibérie, miocène, Arctique, genèse de la flor

Secondary toroidal vortices above seamounts

The classical Taylor-Couette flow appears in a homogeneous fluid between two coaxial cylinders rotating with different angular velocities. The stability loss by a Taylor-Couette flow leads to a bifurcation and generation of Taylor toroidal vortices. In this study we consider an analog to this effect in the case of seamounts in a homogeneous ocean on a f-plane. A seamount is approximated by two coaxial cylinders with heights h1, h2 standing one upon the other, the lower cylinder having a larger diameter. Taylor-Couette flow forms in a circular area above the ledge as follows from the differential squeezing of background vorticity above topography. The essential difference from the classical Taylor-Couette flow is the additional background rotation. We demonstrate that in this model ocean a current bifurcation in a circular area above a seamount ledge leads to the generation of toroidal vortices, also known as Taylor vortices in Taylor-Couette flows

Improving Urban Public Operation: Experience Of Rostov-On-Don (Russia)

This paper estimates experience of development of urban public transport in city Rostov-on- Don, Russia. The main aims of policy of municipal authorities on reforming public transport are analysed. The integrated decision of a problem included achievement of the following purposes: creation most appropriate structure of management of city public transport, change of form of ownership of public transport operators, improvement of competition on the entry of market of transport services, optimization of a routes network of public transport.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

The Transformation of Social and Cultural Space in the Context of the Development of Transport Corridors

This article discusses the methodology of analysis and forecasting of complex spatial systems, taking into account a lot of economic, social and cultural relationships that determine the specifics of the individual territories’ development. Particular attention is paid to the formation of specific zones on the basis of urban settlements along the path of transport corridors. In this regard, the authors introduce the concept of ”urban renewal centers” and give a definition. For its disclosure, the methodological part provides a list of related concepts, defines their boundaries and relationships, and also reveals the essence of the definitions of ‘transport corridor’ and ‘zone of transport corridor’. The authors proposed the use of vector estimates for the analysis of heterogeneous spatial systems of extended information volumes with the inclusion of sociological data and problem-oriented adaptation of visualization and processing of graphic data. As a result of a new, more detailed statement of the problem, we can go on to assess the prospects for the development of space for the complex and heterogeneous macro-regional and transboundary transport corridor Ural — Northern Kazakhstan. The study has fixed that development of urban renewal centers acts as a driver for the development of social and cultural spheres, as well as general economic conditions. The social and cultural transformation of urban settlements over time begins to determine their economic development potential. Such settlements are becoming centers of gravity in the labor market with many far-reaching development scenarios. Keywords: regional development, urban settlements, urban renewal, transport corridor, visualizatio

Internet and Social Media As a Tool of Aggregating Protest Moods

The ongoing sociocultural transformations contribute to the present the problem of the society and power relationship. Due to the changing forms, methods and channels of communication, including political communication, this article considers the role and place of the Internet, social media in aggregating protest moods. Since there is a lack of a consensus in the scientific literature on the phenomenon of political protest, the authors present a theoretical interpretation within the framework of political sociology supported by the Russian researchers’ developments of recent years. Protest political activity is seen as a form of political participation and communication with the authorities. The purpose of the research is to reveal the role of information technology and social media in aggregating protest moods on the basis of analyzing online publications. The scientific novelty is conditioned by a multifaceted study of the role and place of the Internet and social media in aggregating protest moods, the role of horizontal and vertical communications during protests. Methods of the research are theoretical and methodological analysis, ontological and system analysis and questionnaire survey. The sociological study has shown how the society’s perception of protests changes in the context of the virtual political space development, which in certain periods becomes more important than the physical political space. Keywords: political protest, protest activity, protest moods, social media, sociological stud

First Supramolecular Sensors for Phosphonate Anions

Fluorescent tripodal anion sensors with a 1,3,5-triethylbenzene core display a turn-on fluorescence response to phosphonate and phosphate anions and may be used as optical sensors. The properties of the receptors and sensors as well as their anion binding behavior were investigated both in solution and in solid state. The turn-on fluorescence response can be leveraged in sensing of phosphate anions and, most importantly, hydrolysis products of the nerve gas sarin, isopropyl methylphosphonate (IMP), and methylphosphonate (MP). The fluorescence signal amplification in the presence of anions allows for application of these molecules in a sensor microarray suitable for high-throughput screening.NSF CHE 0750303, EXP-LA 0731153BGSU (TIE Grant)Chemistr

Population dynamics of the Taimyr reindeer population

The Taimyr herd of wild reindeer (Rangifer tarandus tarandus L.) is one of the three largest herds of wild Rangifer in the world, and numbered about 600 000 in 1993. The herd grew continuously from 1959 to 1990, and is now stable due primarily to intensive commercial harvesting along the Khatanga River. Meat from the commercial harvest is processed and sold in population centers in the northern Krasnoyarsk region, particularly Norilsk. The herd has expanded its range to about 1.5 million km2, but movements to the southwestern portion of the winter range may have been impeded by pipeline, road and railroad construction, and winter shipping of ore on the lower Yenisey River