Neighbours of Einstein's Equations: Connections and Curvatures

Once the action for Einstein's equations is rewritten as a functional of an SO(3,C) connection and a conformal factor of the metric, it admits a family of ``neighbours'' having the same number of degrees of freedom and a precisely defined metric tensor. This paper analyzes the relation between the Riemann tensor of that metric and the curvature tensor of the SO(3) connection. The relation is in general very complicated. The Einstein case is distinguished by the fact that two natural SO(3) metrics on the GL(3) fibers coincide. In the general case the theory is bimetric on the fibers.Comment: 16 pages, LaTe

The effect of clay morphology on water relaxation

The frequency dependence of the permittivity of water in calcium kaolinite (clay) is measured. It is shown that two mechanisms contribute to dipole relaxation of water. One refers to water in the free volume of pores in the clay. The other is associated with bound water covering the porous surface. Experimental data are treated in terms of a fractal model of the medium. The frequency dependence of the permittivity in a wide range of water content in the clay is accounted for theoretically. © 2001 MAIK "Nauka/Interperiodica"

The low-temperature dynamic crossover in the dielectric relaxation of ice I<inf>h</inf>

© 2017 the Owner Societies. Based on the idea of defect migration as the principal mechanism in the dielectric relaxation of ice I h , the concept of low-temperature dynamic crossover was proposed. It is known that at high temperatures, the diffusion of Bjerrum and ionic defects is high and their movement may be considered to be independent. Simple switching between these two mechanisms leads to a dynamic crossover at ∼235 K. By introducing coupling between the Bjerrum and ionic defects, it is possible to describe the smooth bend in the relaxation time at low temperatures in ice I h . However, because the mobility of Bjerrum orientation defects slows down at low temperatures, they may create blockages for proton hopping. The trapping of ionic defects by L-D defects for a long period of time leads to an increase in the relaxation time and causes a low-temperature crossover. This model was validated by experimental dielectric measurements using various temperature protocols

Dynamic and structural properties of oxyethylated isononylphenols

© 2016Diffusion coefficients, dielectric relaxation times and refraction coefficients were measured, and activation energies of translational and rotational mobilities were determined for a series of oxyethylated phenols (neonols AF9-n) p-C9H19C6H4-O(CH2CH2O)nH, n = 4, 6, 8, 9, 10, 12, at different temperatures. The results demonstrated the existence of contraction and transition phenomena that changed the structure of neonol molecules at n ∼ 9 from a zigzag to a meander form

Arrangement of cooperation between labour market and regional vocational education system

© 2018, Emerald Publishing Limited. Purpose: Modern educational environment in the system of vocational education focuses on the requirements of labour market and those of employers to the content of graduates’ professional competencies. Thus, the purpose of this paper is to develop practical guidance on the arrangement of cooperation between labour market and regional vocational education system. Design/methodology/approach: Participative approach allowed considering the cooperation between labour market and regional system of vocational education as the process aimed at creating management tools for formation, use, development of human resources. The research involved 300 teachers, 400 students, 100 employers, who found out the effectiveness criteria for the cooperation between labour market and vocational education system. Findings: The findings reveal national models characteristics and universal tools for cooperation between vocational education institutions and enterprise. National models characteristics allow identifying the most advantageous cooperation tools; comparing suggested tools with the experience of others and thereby assessing their relevance and implementation risks. Research limitations/implications: The research results allow us to plan strategies for further studies of this problem, which are related to the development of models for cooperation between labour market and vocational education system. Practical implications: The identification of universal tools for cooperation between vocational education institutions and enterprise promotes the integration of national vocational education systems into national educational space. The materials of the paper can be useful for university leaders and professors; employees of centres for professional advancement and retraining in selecting and structuring the content of academic and teaching staff’s advanced training. Social implications: The revealed criteria contribute to vocational education programmes integration, connection between professional and educational standards, students’ professional identity. Originality/value: The effectiveness of the cooperation between labour market and vocational education system will be improved by studying national models and identifying the most advantageous cooperation tools (modular training, voluntary social/ecological year, educational resources integration, state and public management, clustering vocational education institutions and industry companies). This will allow comparing the suggested tools for collaboration between labour market and vocational education system with the experience of others and thereby assess their relevance and implementation risks. Improving the cooperation between labour market and vocational education system will be successful provided that universal tools for cooperation (socio-economic, educational, practical, innovative and technological) are identified, which promotes the integration of national vocational education systems into national educational space. The effectiveness of cooperation between labour market and vocational education system will increase on condition of criterion assessment (clustering, subjectivity, transdisciplinarity), promoting vocational education programmes integration, connection between professional and educational standards, students’ professional identity, students’ engagement in the development and implementation of research and production projects, stepped formation of professional competencies

On the non-Abelian Stokes theorem for SU(2) gauge fields

We derive a version of non-Abelian Stokes theorem for SU(2) gauge fields in which neither additional integration nor surface ordering are required. The path ordering is eliminated by introducing the instantaneous color orientation of the flux. We also derive the non-Abelian Stokes theorem on the lattice and discuss various terms contributing to the trace of the Wilson loop.Comment: Latex2e, 0+14 pages, 3 figure

Electrochemical Sensors for Vanadium Determination

© Published under licence by IOP Publishing Ltd. This paper is dedicated to the problem of vanadium (V) determination by the means of voltammetry. The comparison of results obtained for two types of sensor: volume glassy-carbon electrode and screen printed carbon electrode are presented. The experimental data is recorded using the hardware and software of Novocontrol (Germany): electrochemical interface POT/GAL 15V 10A, frequency response analyzer Alpha-A, and software for data collection and data processing WinDETA. Two three-electrode cells has been studied: for the first one the bulk glassy carbon electrode, and for the second one the screen printed electrodes has been used as the working electrode. In the first case the reference electrode has been made from silver chloride and the counter electrode from steel wire. In case of the screen printed electrodes, the electrodes were placed on the same plate. The peak of vanadium (V) was obtained under the potential of 1.3 V. It was found that the growth of the vanadium concentration increases magnitude of the cathode current measured then the mentioned potential is applied. The screen printed carbon electrodes provides better sensitivity in comparison with the volume glassy-carbon electrodes due to the more explicit vanadium potential peak

Photostimulated phenomena in relaxors

The action of illumination on the conducting and dielectric properties of lead magnoniobate was investigated. The photostimulated currents were examined and the spectral dependence of photoconductivity in the region of diffuse phase transition was obtained. It was found that the illumination affects the dielectric properties and that its action is memorized at temperatures below room temperature. The role of defect states in the formation of relaxor properties is discussed on the basis of the obtained data. © 2003 MAIK "Nauka/Interperiodica"

Remarks on Conserved Quantities and Entropy of BTZ Black Hole Solutions. Part II: BCEA Theory

The BTZ black hole solution for (2+1)-spacetime is considered as a solution of a triad-affine theory (BCEA) in which topological matter is introduced to replace the cosmological constant in the model. Conserved quantities and entropy are calculated via Noether theorem, reproducing in a geometrical and global framework earlier results found in the literature using local formalisms. Ambiguities in global definitions of conserved quantities are considered in detail. A dual and covariant Legendre transformation is performed to re-formulate BCEA theory as a purely metric (natural) theory (BCG) coupled to topological matter. No ambiguities in the definition of mass and angular momentum arise in BCG theory. Moreover, gravitational and matter contributions to conserved quantities and entropy are isolated. Finally, a comparison of BCEA and BCG theories is carried out by relying on the results obtained in both theories.Comment: PlainTEX, 20 page

Результаты современных отечественных наземных радиолокационных исследований во внутренних районах Восточной Антарктиды

Overview of the Russian remote sensing investigations in the East Antarctic inland and the subglacialLakeVostokis described in the paper. Ground-based radio-echo sounding was carried out along the logistic traverse routes “Mirny – Vostok” and “Progress – Vostok”. The main features of the subice landscape and the ice sheet were revealed. Besides, two subglacial lakes were discovered there. They were named asKomsomolskoeLakeandPionerskoeLake. Bedrock topography, the depth of the lake, ice thickness and other maps were compiled on the results of the geophysical investigations in theLakeVostok. The lake coastal line was also detected. Eleven islands and 56 small water caves were discovered in theLakeVostokarea. All the geophysical data are pointed the lake is completely isolated.В статье сделан обзор современных отечественных наземных дистанционных исследований, выполненных с целью изучения внутренних районов Восточной Антарктиды и подледникового озера Восток. Наземные радиолокационные исследования выполнялись по маршрутам вдоль трасс следования санно-гусеничных походов «Мирный–Восток» и «Прогресс–Восток». Результаты этих работ позволили выявить основные особенности подледного ландшафта и ледникового покрова в региональном масштабе. Помимо этого, было выявлено два подледниковых водоема: озера Пионерское и Комсомольское. Работы в районе озера Восток позволили построить комплект карт мощности ледникового покрова, глубин озера и подледной топографии, а также установить береговую линию озера. В пределах его акватории выявлено 11 островов, а вокруг озера Восток выявлено 56 незначительных по размерам подледниковых водоемов. Имеющиеся данные указывают на то, что озеро Восток представляет собой изолированную систему