Composite S-Brane Solutions On Product Of Ricci-Flat Spaces

A family of generalized $S$-brane solutions with orthogonal intersection rules and $n$ Ricci-flat factor spaces in the theory with several scalar fields and antisymmetric forms is considered. Two subclasses of solutions with power-law and exponential behaviour of scale factors are singled out. These subclasses contain sub-families of solutions with accelerated expansion of certain factor spaces. The solutions depend on charge densities of branes, their dimensions and intersections, dilatonic couplings and the number of dilatonic fields.Comment: To appear in GR

Prospects for the Ferronickel Production Development from the Urals Oxidized Nickel Ores

Methods of ore processing are divided into hydro- and pyrometallurgical. The latter method is more common. Ferronickel is seeing high demand at present. It is produced by reducing electric smelting of previously calcined ore. This method is typically used because of the composition and quality of the products obtained (there is a particularly large market for Ferronickel of the standard ISO 6501:1988, containing at least 15% Ni). Processing technologies for converting poor oxidized nickel ores into ferronickel offer significant advantages, reducing the environmental impact and energy consumption, and increase the recovery of valuable metals. This study considers the processing technology of serpentinite ores, which includes: ore preparation (averaging, crushing and screening, drying); roasting a mixture of dried ore and crushed dolomite (flux) in tubular rotary kilns; melting of hot cinder with the addition of a reducing agent in an ore-smelting direct-current electric furnace to produce a rough ferronickel; refining ferronickel from impurities of carbon, silicon, sulfur, phosphorus, chromium was substantiated. During the industrial testing of electric smelting of calcined ores from the Ural deposits, ferronickel, containing (in wt. %) 8.9-15.5 Ni, 1.1 Cr, 0.17 Co, 0.1 S, 0.1 C was produced. Nickel extraction in ferronickel was 96.1 %, cobalt – 89.1 %. Keywords: ore, nickel, production, heating, roasting and reduction, phase transition

The Influence of Modes of Deposition of Coatings on the Corrosion Resistance of Welded Joints of Steels in Acidic Media

In this work, effect of welding on corrosion of welded joints of austenitic steel 12KH18N10T. It is shown that the use of pulsed - arc welding steel 12KH18N10T allows you to create a protective coating with dispersed structure with less thermal impact on the zone of the welded joint. Coating is of such structure allows 1.5 to 6 times to reduce the corrosion rate of welded joints of steel 12KH18N10T in active chemical environments. Pulse the process of deposition of coatings on welded joint of steels can be effectively used for the protection against corrosion in the repair of equipment of chemical industry. The results obtained can be recommended for use when welding a protective corrosion - resistant coatings on working surfaces of equipment of chemical productions

Decay of metastable current states in one-dimensional resonant tunneling devices

Current switching in a double-barrier resonant tunneling structure is studied in the regime where the current-voltage characteristic exhibits intrinsic bistability, so that in a certain range of bias two different steady states of current are possible. Near the upper boundary V_{th} of the bistable region the upper current state is metastable, and because of the shot noise it eventually decays to the stable lower current state. We find the time of this switching process in strip-shaped devices, with the width small compared to the length. As the bias V is tuned away from the boundary value V_{th} of the bistable region, the mean switching time \tau increases exponentially. We show that in long strips \ln\tau \propto (V_{th} -V)^{5/4}, whereas in short strips \ln\tau \propto (V_{th} -V)^{3/2}. The one-dimensional geometry of the problem enables us to obtain analytically exact expressions for both the exponential and the prefactor of \tau. Furthermore, we show that, depending on the parameters of the system, the switching can be initiated either inside the strip, or at its ends.Comment: 12 pages, 5 figures, update to published versio

Definition and characteristics of personality-oriented approach to teaching physical education in institutions of higher education

In the beginning of the article briefly indicates what a student-centered teaching in higher education; following the explanation of relevance, is increasing the knowledge base on student-centered learning: its function, criteria for the conduct of teaching staff; in conclusion, displays the importance of student-centered learningВ начале статьи кратко указывается, что из себя представляет личностно-ориентированное обучение в высшем образовании; после разъяснения актуальности, идет расширение базы знаний о личностно-ориентированном обучении: его функции, критерии поведения педагогического состава; в заключении выводится важность применения личностно-ориентированного обучени

The activity-based approach to achieving theoretical and practical consensus in pedagogy of N. F. Talyzina

The relevance of the problem under study is based on the necessity to solve the permanent problem of the unity of theory and practice in the content of students’ cognitive activity in the modern conditions. The purpose of the article is to analyze and to generalize the main concepts of pedagogy by N.F. Talyzina for implementation of the activity-based approach as a productive means of achieving theoretical and practical consensus in the process of forming students’ cognitive activity. The lead approach to studying this problem is the activity-based approach which adequately expresses the objective and the essence of our research. The article is based on the concepts of pedagogy by N.F. Talyzina and reveals the conceptual and instrumental components of implementing the activity-based approach as a productive means of achieving theoretical and practical consensus in the process of forming students’ cognitive activity. The materials of the article can be useful in modeling, designing and constructing a pedagogical concept aimed at achieving the balance between theoretical and practical components within the process of carrying out educational activity. © 2016 Chapaev et al

The relationship competence of the teacher of physical culture and student motivation for physical self-improvement

This article describes the characteristics of the profession of teacher, derived actuality, the concept of physical development and self-improvement, disassembled, as this type of activity was equated with a hobby among young people, after made to the relationship between motivation to self-improvement and teacher, what is its importance and role and what personal qualities-competencies he must have finally summed up the conclusionВ данной статье рассмотрена характеристика профессии педагог, выведена актуальность, раскрыто понятие физического развития и самосовершенствования, разобрано, как данный вид деятельности стал приравниваться к хобби среди молодежи, после, проведена взаимосвязь между мотивацией к самосовершенствованию и педагогом, в чем его значимость и роль и какими личностными качествами-компетенциями он должен обладать, в заключение подведен выво

ENSURING ECONOMIC SECURITY OF RUSSIA IN THE CONTEXT OF AFRICAN DEVELOPMENT TRENDS: PROBLEMS AND PROSPECTS

Abstract Purpose: A new scientific problem is posed and substantiated: the need to take into account the African economic development trends in the system of ensuring the economic security of Russia. In this context, in order to assess the security of the national economy and the competitive position of Russia, the results of scientific studies of the main development trends and threats in Africa, the position of various countries on the African continent are analyzed. Methodology: The authors are based on the analysis of current scientific literature, government official documents, and statistical reports. The main methods of research are analytical review, comparison, systematic approach, cultural and civilizational approach. Result: The article substantiates the position that taking into account the development trends of the African continent is an important component in the system of assessing the national economic security of Russia in the current period and in the future, ensuring competitiveness and strengthening the economic sovereignty of Russia, analyzing the potential of interaction with African countries in the management practice. Applications: This research can be used for the universities, teachers and education students. Novelty/Originality: The authors formulate the main directions of the activation of scientific research and concentration of practical efforts to improve the national economic security of Russia in the context of the development trend of the African continent