Статичні змішувачі в циркуляційних системах промивальної рідини бурових установок

The work of three static mixer designs in flushing fluid circulation systems of drilling rigs was studied taking into account the basic parameters of drilling mud. Modelling was carried out, and parametric slurry fields were obtained in the pipe work area, that is in a static mixer installation site and in the area of pipeline behind it. The following models were obtained: velocity fields, vorticity fields, turbulence intensity fields, scale turbulence fields along the travel path. Graphs of the parameters changes regarding the tube axis were plotted. The comparative analysis of patterns and curves was carried out. The rational design of static mixer for obtaining of optimum mud mixing technology features is grounded.Досліджено роботу трьох конструкцій статичного змішувача в циркуляційній системі промивальної рідини бурових установок, ураховуючи основні параметри бурового розчину. Виконано моделювання та отримано параметричні поля гідросуміші у робочій зоні труби, а саме в місці установки статичного змішувача і в зоні трубопроводу за ним. Отримано моделі: поля швидкостей, поля завихреності, поля інтенсивності турбулентності, поля масштабу турбулентностей по довжині шляху перемішування. Побудовано графіки зміни досліджуваних параметрів відносно осі труби. Виконано порівняльний аналіз моделей та кривих. Обґрунтовано раціональну конструкцію статичного змішувача для отримання оптимальних технологічних характеристик перемішування бурового розчину

Universities of the North-western federal district in Russian-Finnish research cooperation

This article focuses on the cooperation between universities of the North-western federal district (NWFD) of the Russian Federation, Sweden, and Finland, its intensity and territorial differentiation. The analysis was conducted on the basis of public domain information on the international activity of universities available on their official websites. The authors identify the principle areas and leading centres of such cooperation. The NWFD universities have significant experience in cooperation with Finnish universities. Cooperation with Swedish universities is proved to be less developed. Approximately 50 NFWD universities, 29 of which are located in Saint Petersburg, are involved in cooperation; most NWFD universities do not cooperate with the mentioned countries. Such low degree of cooperation in the field of education is a serious inhibiting factor, which reduces competitiveness on the modern market of educational services

International research cooperation in the Baltic region: a scientometric analysis

This article examines the processes of international research cooperation in the Baltic Sea region. It focuses on research works published in the leading periodicals in 1993-2012. The empirical material is collected from the world’s largest abstract and citation database, SciVerse Scopus, which makes it possible to evaluate macroindicators at the national and global levels as well as the contribution of scholars to the global progress. The article also offers an assessment of the efficiency of research activities in the Baltic Sea region countries. It is based on a number of scientometric indicators that reflect the performance of universities in terms of research journal publications and the development of research cooperation in the field of Baltic studies. The authors consider the dynamics of research contribution and academic cooperation in the Baltic Sea countries in four leading fields - i. e. agricultural and biological sciences, Earth sciences, ecology and social sciences presented in the SciVerse Scopus scientometric database. The article provides a map of research cooperation in the Baltic Sea region

Analysis of agriculture sustainable development in Russia

The article is focused on determining the current situation in Russia on the way to achieving the goals of sustainable development in agriculture. When analyzing the literature, it was revealed that most of the goals and objectives of sustainable development are already, to a greater or lesser degree, incorporated into the main strategic and program documents in Russia. Achievements in the implementation of SDG 2 “End hunger, achieve food security and improved nutrition and promote sustainable agriculture” were considered. Statistical indicators of agriculture sustainable development in Russia are analyzed. The principles for development of the agrifood systems sustainability concept are formulated and presented. In the last century and a half, the main task of Russia in country’s food security has been to feed its population. At the present day, it can be stated that this problem has been mainly solved

DEVELOPMENT OF A MODEL FOR THE PRODUCTION OF METAL-POWDER COMPOSITIONS BASED ON CO-CR ALLOYS BY ELECTROEROSIVE DISPERSION

Abstract. The main requirement for powders for additive 3d technologies is the spherical shape of theparticles. Such particles are most compactly packed into a certain volume and ensure the "fluidity" of the powder composition in the supply systems of the material with minimal resistance. The wide use of the EED method for processing metal waste into powders for the purpose of their reuse and application in additive technologies is hampered by the lack in the scientific and technical literature of full-fledged information on the effect of the initial composition, regimes and media on the properties of powders and technologies of practical application. Therefore, in order to develop technologies for the reuse of electroerosive powders and to evaluate the effectiveness of their use, complex theoretical and experimental studies are required. The aim of the work was to develop a model for the production of metal powder compositions on the basis of Co-Cr alloys by electroerosive dispersion. Based on the results of the conducted studies, it has been established that the optimum parameters for the process of obtaining powder materials by the method of electroerosive dispersion of butyl alcohol are: capacitance of discharge capacitors 48 μF, voltage on electrodes 100 V, repetition rate of pulses 120 Hz

Examination of evidence for collinear cluster tri-partition

In a series of the experiments at different time-of-flight spectrometers of heavy ions we have observed manifestations of a new at least ternary decay channel of low excited heavy nuclei. Due to specific features of the effect, it was called collinear cluster tri-partition (CCT). The experimental results obtained initiated a number of theoretical articles dedicated to different aspects of the CCT. We compare theoretical predictions with our experimental data, only partially published so far. The model of one of the most populated CCT modes that gives rise to the so called "Ni-bump" is discussed. Detection of the 68-72Ni fission fragments with a kinetic energy E<25 MeV at the mass-separator Lohengrin is proposed for an independent experimental verification of the CCT.Comment: 16 pages, 14 figure

Magnetism of coupled spin tetrahedra in ilinskite-type KCu5_{5}O2_2(SeO3_3)2_2Cl3_3

Synthesis, thermodynamic properties, and microscopic magnetic model of ilinskite-type KCu$_{5}$O$_2$(SeO$_3$)$_2$Cl$_3$ built by corner-sharing Cu$_4$ tetrahedra are reported, and relevant magnetostructural correlations are discussed. Quasi-one-dimensional magnetic behavior with the short-range order around 50\,K and the absence of long-range order down to at least 2\,K is observed experimentally and explained in terms of weakly coupled spin ladders (tubes) with a complex topology formed upon fragmentation of the tetrahedral network. This fragmentation is rooted in the non-trivial effect of the SeO$_3$ groups that render the Cu--O--Cu superexchange strongly ferromagnetic.Comment: 9 pages, 7 figure