Chronopotentiometry at platinum electrode in KF-NaF-AlF3-Al2O3 melt

Some features of the mechanism of the anode process on platinum in KF–NaF–AlF3–Al2O3 melt at 750–780 °C depending on the of anodic current density (0.5 mA/cm2 to 2.0 A/cm2) and anodic pulse duration have been studied using chronopotentiometry method. In curves of change in the platinum anode potential a small peak at current densities of 10–30 mA/cm2 and a clear peak at current densities of 0.5–2.0 A/cm2 are recorded when the current is cut on. Analysis of dependencies of the transition time on the current density indicates that the first peak in curve is associated with the formation of an oxide compound on the platinum surface, and the second one is related to hindering the diffusion for delivery of electroactive particles to its surface.The study was supported by the Russian Foundation for Basic Research (grant № 13–03–00829 A)

EFFECTIVENESS HARBOUR TUG FLEET: PROBLEM FORMULATION AND METHODOLOGY OF ITS SOLUTION

The article deals with the current problem of improving the effectiveness of the harbour tug fleet. The methodology of the selection of optimal structure of the tug assistance has been suggested. It is based on the methods of statistical modelling, the queuing theory and the theory of the ship design, as well as algorithms developed by the authors. The method of calculating forces, which act on the ships during their movement to the port berths, and the transfer of these forces to the required total bollard pull of tugs is described. The method for calculating the economic performance of the harbour tugs used in harbour towage is considered. The algorithm for the development of the order with the determination of the required number of tugs to carry out towing operations in the current hydrometeorological conditions of the port is suggested. The model of the functioning of the harbour tugs is developed. The optimization problem of the determination of the required structure of the harbour tug fleet is formulated and solved. The findings of the study results are suggested for the optimization of the existing or renewed tug assistance of the port, selection of the design characteristics of harbour tugs on the conceptual stages design

ФЕНОМЕНОЛОГІЯ ВІДМИВАННЯ КОШТІВ В УКРАЇНІ

The article investigates the problems of the spread of complex socio-economic phenomenon-money laundering in Ukraine. The attention is focused on the results of the fifth round of mutual evaluation of Ukraine in the sphere of AML by the Committee of the Council of Europe MONEYVAL and conclusions on the lack of effectiveness of the national mechanism of combating money laundering in Ukraine. The necessity of monitoring and conducting appropriate macroeconomic and criminological analysis on the basis of scientific knowledge of the phenomenon of «money laundering», the factors of its manifestation and spread in Ukraine. As a methodology for the study of money laundering in Ukraine as a socio-economic phenomenon, the application of phenomenology based on the combination of the philosophical method of knowledge of the phenomenon in reality based on the essential characteristics of its nature, and criminology — the doctrine of crime. The results of the survey of specialists of the law enforcement system in the field of anti-money laundering are chosen as an empirical basis. The analysis covers several groups of indicators, in particular, characterizing the spread of money laundering in the country as a whole, and the vulnerability of individual sectors of the economy. Attention is focused on the significant spread of the phenomenon of money laundering in Ukraine, as evidenced by 84.5% of respondents, and the most vulnerable is determined by the credit and financial sector (82.0%). Based on the use of a special group of indicators, the analysis of the connection of money laundering with other socially dangerous socio-economic phenomena: corruption, the shadow economy, capital flight, organized crime and the like. The article focuses on the extreme demand of corrupt officials on laundering of corruption revenues, as noted by 85.4% of respondents. It is concluded that it is necessary to introduce fundamental changes regarding the system of combating money laundering in Ukraine.Исследуются проблемы распространения сложного социально-экономического явления — отмывание денег в Украине. Акцентировано внимание на результатах пятого раунда взаимной оценки Украины в сфере ПОД Комитетом Совета Европы MONEYVAL и выводах относительно недостаточной эффективности национального механизма противодействия отмыванию денег в Украине. Указано на необходимость мониторинга и проведения соответствующего макроэкономического и криминологического анализа на основе научного познания феномена «отмывания денег», факторов его проявления и распространения в Украине. На основе использования специальной группы индикаторов осуществлен анализ связанности отмывания денег с другими общественно опасными социально-экономическими явлениями: коррупция, теневая экономика, «бегство» капитала, организованная преступность и тому подобное. Акцентировано на чрезвычайном спросе коррупционеров по отмыванию коррупционных доходов, о чем отмечают 85,4 % респондентов. Сделан вывод о необходимости введения фундаментальных изменений относительно системы противодействия отмыванию денег в Украине.Досліджуються проблеми поширення складного соціально-економічного явища — відмивання коштів в Україні. Акцентовано увагу на результатах п’ятого раунду взаємної оцінки України у сфері ПВК Комітетом Ради Європи MONEYVAL і висновках щодо недостатньої ефективності національного механізму протидії відмиванню коштів в Україні. Зазначено на необхідності моніторингу і проведення відповідного макроекономічного й кримінологічного аналізу на основі наукового пізнання феномену «відмивання коштів», факторів його прояву і поширення в Україні. Методологією дослідження відмивання коштів в Україні як соціально-економічного явища обґрунтовується застосування феноменології, що базуватиметься на поєднанні філософського методу пізнання феномену в реальній дійсності на основі сутнісних характеристик його природи, і кримінології — учення про злочин. Емпіричною основою обрано результати анкетування фахівців правоохоронної системи у сфері протидії відмиванню коштів. Аналізом охоплюється декілька груп індикаторів, зокрема ті, які характеризують поширення відмивання коштів як у цілому по країні, так і вразливість окремих галузей економіки. Акцентовано увагу на значному поширенні феномену відмивання коштів в Україні, про що зазначає 84,5 % опитаних, а найбільш вразливою визначено кредитно-фінансову сферу (82,0 %). На основі використання спеціальної групи індикаторів здійснено аналіз пов’язаності відмивання коштів з іншими суспільно небезпечними соціально-економічними явищами: корупція, тіньова економіка, «втеча» капіталу, організована злочинність тощо. Акцентовано на надзвичайному попиті корупціонерів щодо відмивання корупційних доходів, про що зазначають 85,4 % респондентів. Зроблено висновок про необхідність запровадження фундаментальних змін щодо системи протидії відмиванню коштів в Україні

Electronic Structure of New Multiple Band Pt-Pnictide Superconductors APt3P

We report LDA calculated band structure, densities of states and Fermi surfaces for recently discovered Pt-pnictide superconductors APt3P (A=Ca,Sr,La), confirming their multiple band nature. Electronic structure is essentially three dimensional, in contrast to Fe pnictides and chalcogenides. LDA calculated Sommerfeld coefficient agrees rather well with experimental data, leaving little space for very strong coupling superconductivity, suggested by experimental data on specific heat of SrPt3P. Elementary estimates show, that the values of critical temperature can be explained by rather weak or moderately strong coupling, while the decrease of superconducting transition temperature Tc from Sr to La compound can be explained by corresponding decrease of total density of states at the Fermi level N(E_F). The shape of the density of states near the Fermi level suggests that in SrPt3P electron doping (such as replacement Sr by La) decreases N(E_F) and Tc, while hole doping (e.g. partial replacement of Sr with K, Rb or Cs, if possible) would increase N(E_F) and possibly Tc.Comment: 5 pages, 5 figure

Instanton Number Calculus on Noncommutative R^4

In noncommutative spaces, it is unknown whether the Pontrjagin class gives integer, as well as, the relation between the instanton number and Pontrjagin class is not clear. Here we define ``Instanton number'' by the size of $B_{\alpha}$ in the ADHM construction. We show the analytical derivation of the noncommuatative U(1) instanton number as an integral of Pontrjagin class (instanton charge) with the Fock space representation. Our approach is for the arbitrary converge noncommutative U(1) instanton solution, and is based on the anti-self-dual (ASD) equation itself. We give the Stokes' theorem for the number operator representation. The Stokes' theorem on the noncommutative space shows that instanton charge is given by some boundary sum. Using the ASD conditions, we conclude that the instanton charge is equivalent to the instanton number.Comment: 29 pages, 7 figures, some statements in Sec.4.3 correcte

Instanton Number of Noncommutative U(n) gauge theory

We show that the integral of the first Pontrjagin class is given by an integer and it is identified with instanton number of the U(n) gauge theory on noncommutative ${\bf R^4}$. Here the dimension of the vector space $V$ that appear in the ADHM construction is called Instanton number. The calculation is done in operator formalism and the first Pontrjagin class is defined by converge series. The origin of the instanton number is investigated closely, too.Comment: 6 color figures, 27 pages, some comments and references are added,typos fixe

Topological Vector Symmetry of BRSTQFT and Construction of Maximal Supersymmetry

The scalar and vector topological Yang-Mills symmetries determine a closed and consistent sector of Yang-Mills supersymmetry. We provide a geometrical construction of these symmetries, based on a horizontality condition on reducible manifolds. This yields globally well-defined scalar and vector topological BRST operators. These operators generate a subalgebra of maximally supersymmetric Yang-Mills theory, which is small enough to be closed off-shell with a finite set of auxiliary fields and large enough to determine the Yang-Mills supersymmetric theory. Poincar\'e supersymmetry is reached in the limit of flat manifolds. The arbitrariness of the gauge functions in BRSTQFTs is thus removed by the requirement of scalar and vector topological symmetry, which also determines the complete supersymmetry transformations in a twisted way. Provided additional Killing vectors exist on the manifold, an equivariant extension of our geometrical framework is provided, and the resulting "equivariant topological field theory" corresponds to the twist of super Yang-Mills theory on Omega backgrounds.Comment: 50 page

Interplay between magnetic properties and Fermi surface nesting in iron pnictides

The wave-vector q and doping (x,y) dependences of the magnetic energy, iron moment, and effective exchange interactions in LaFeAsO{1-x}F{x} and Ba{1-2y}K{2y}Fe2As2 are studied by self-consistent LSDA calculations for co-planar spin spirals. For the undoped compounds (x=0, y=0), the minimum of the calculated total energy, E(q), is for q corresponding to stripe antiferromagnetic order. Already at low levels of electron doping (x), this minimum becomes flat in LaFeAsO{1-x}F{x} and for x>=5, it shifts to an incommensurate q. In Ba{1-2y}K{2y}Fe2As2, stripe order remains stable for hole doping up to y=0.3. These results are explained in terms of the band structure. The magnetic interactions cannot be accurately described by a simple classical Heisenberg model and the effective exchange interactions fitted to E(q) depend strongly on doping. The doping dependence of the E(q) curves is compared with that of the noninteracting magnetic susceptibility for which similar trends are found.Comment: 17 pages, 5 figure

A & B model approaches to surface operators and Toda theories

It has recently been argued by Alday et al that the inclusion of surface operators in 4d N=2 SU(2) quiver gauge theories should correspond to insertions of certain degenerate operators in the dual Liouville theory. So far only the insertion of a single surface operator has been treated (in a semi-classical limit). In this paper we study and generalise this proposal. Our approach relies on the use of topological string theory techniques. On the B-model side we show that the effects of multiple surface operator insertions in 4d N=2 gauge theories can be calculated using the B-model topological recursion method, valid beyond the semi-classical limit. On the mirror A-model side we find by explicit computations that the 5d lift of the SU(N) gauge theory partition function in the presence of (one or many) surface operators is equal to an A-model topological string partition function with the insertion of (one or many) toric branes. This is in agreement with an earlier proposal by Gukov. Our A-model results were motivated by and agree with what one obtains by combining the AGT conjecture with the dual interpretation in terms of degenerate operators. The topological string theory approach also opens up new possibilities in the study of 2d Toda field theories.Comment: 43 pages. v2: Added references, including a reference to unpublished work by S.Gukov; minor changes and clarifications