Hyperbolic chaos in self-oscillating systems based on mechanical triple linkage: Testing absence of tangencies of stable and unstable manifolds for phase trajectories

Dynamical equations are formulated and a numerical study is provided for self-oscillatory model systems based on the triple linkage hinge mechanism of Thurston -- Weeks -- Hunt -- MacKay. We consider systems with holonomic mechanical constraint of three rotators as well as systems, where three rotators interact by potential forces. We present and discuss some quantitative characteristics of the chaotic regimes (Lyapunov exponents, power spectrum). Chaotic dynamics of the models we consider are associated with hyperbolic attractors, at least, at relatively small supercriticality of the self-oscillating modes; that follows from numerical analysis of the distribution for angles of intersection of stable and unstable manifolds of phase trajectories on the attractors. In systems based on rotators with interacting potential the hyperbolicity is violated starting from a certain level of excitation.Comment: 30 pages, 18 figure

A "saddle-node" bifurcation scenario for birth or destruction of a Smale-Williams solenoid

Formation or destruction of hyperbolic chaotic attractor under parameter variation is considered with an example represented by Smale--Williams solenoid in stroboscopic Poincar\'{e} map of two alternately excited non-autonomous van der Pol oscillators. The transition occupies a narrow but finite parameter interval and progresses in such way that periodic orbits constituting a "skeleton" of the attractor undergo saddle-node bifurcation events involving partner orbits from the attractor and from a non-attracting invariant set, which forms together with its stable manifold a basin boundary of the attractor.Comment: 7 pages, 7 figures, 1 tabl

Plykin-like attractor in non-autonomous coupled oscillators

A system of two coupled non-autonomous oscillators is considered. Dynamics of complex amplitudes is governed by differential equations with periodic piecewise continuous dependence of the coefficients on time. The Poincar\'{e} map is derived explicitly. With exclusion of the overall phase, on which the evolution of other variables does not depend, the Poincar\'{e} map is reduced to 3D mapping. It possesses an attractor of Plykin type located on an invariant sphere. Computer verification of the cone criterion confirms the hyperbolic nature of the attractor in the 3D map. Some results of numerical studies of the dynamics for the coupled oscillators are presented, including the attractor portraits, Lyapunov exponents, and the power spectral density.Comment: 11 pages, 9 figure

Scattering of quasi-optical THz beams on spherical MWCNTs aerogels

Results of research of lateral scattering of electromagnetic radiation by aerogel of MWCNTs are presented. Frequency dependences of lateral scattering of THz radiation of spherical MWCNTs aerogels with diameter of 4.5 and 6 mm at frequency range 43-970 GHz are given

Модели финансирования естественных монополий: бюджетное, корпоративное и проектное финансирование

Subject. To ensure sustainable economic development of the country, it is necessary that natural (infrastructure) monopolies develop at a faster pace than other sectors of the economy. The state historically played a major role in financing the infrastructure facilities building, however, in the current tense economic situation a trend is to reduce government spending. In these conditions, for natural monopolies, evaluation and selection of the most effective sources of financing their investment activities become of special importance.Goals. Comparative analysis of typical models of financing of natural monopolies — budgetary, corporative and project financing. Identifying their advantages and disadvantages, and identify areas of the most appropriate and effective application.Methodology. The researching is based on a dialectical approach. The researching used systemic, comparative and institutional approaches.Results. Each of the considered models of financing has its advantages and disadvantages, and also is characterized by its specificity of use. For short-term investment projects, as well as renovation projects for existing infrastructure, it is advisable to implement a corporative financing model. Budgetary financing is applicable for projects with a long payback period and projects with conditionally “negative return on investments” (projects with very long payback period). The model of “project financing” is most effective for the implementation of large-scale projects with medium or long-term payback.Conclusions. It is shown that, in the current economic conditions, the implementation of most of the infrastructure tasks included in the strategy of Russia’s economic development can be achieved mainly through the use of project financing. However, its progress in Russia is hindered by the underdevelopment of the legislative base.Предмет. Для обеспечения устойчивого экономического развития страны необходимо, чтобы естественные (инфраструктурные) монополии развивались опережающими темпами по отношению к  остальным отраслям экономики. Государство исторически играло главную роль в  финансировании строительства объектов инфраструктуры, однако в  условиях текущей напряженной экономической ситуации имеется тенденция к сокращению государственных ассигнований. Для естественных монополий особое значение приобретает оценка и выбор наиболее эффективных источников финансирования своей инвестиционной деятельности.Цели. Сравнительный анализ типовых моделей финансирования естественных монополий — бюджетного, корпоративного и проектного. Выявление их достоинств и недостатков, определение областей наиболее целесообразного и эффективного применения.Методология. Исследование базируется на диалектическом подходе. Также использованы системный, сравнительный и институциональный подходы.Результаты. Каждая из рассмотренных моделей финансирования имеет свои преимущества и  недостатки, а также характеризуется спецификой использования. Для краткосрочных инвестиционных проектов, а также проектов обновления существующих объектов инфраструктуры целесообразно реализовывать модель корпоративного финансирования. Бюджетное финансирование применимо для проектов с длительным сроком окупаемости, а также условно «неокупаемых» проектов (проектов со сверхдлительным сроком окупаемости). Проектное финансирование наиболее эффективно для реализации масштабных проектов со средней или длительной окупаемостью.Выводы. Показано, что в существующих экономических условиях выполнение большинства инфраструктурных задач, заложенных в стратегию экономического развития России, может быть обеспечено преимущественно путем использования проектного финансирования. Однако его развитие в России тормозится неразвитостью законодательной баз

The number of the intraepithelial T cells correlate with the proliferation index in human bulbourethral gland epithelium

Background: Our study has immunohistochemically examined T cells localization and number as well as proliferative activity level for the bulbourethral gland epithelium in men of different ages, using monoclonal antibodies against CD45RO and proliferating cell nuclear antigen (PCNA). Results: We have found that the T cells have been localized mainly in excretory ducts epithelium of the glands in any age group, meanwhile their relative number varies with age. The excretory ducts epithelium has shown a high proliferative activity when in acini the PCNA index has been low. Postnatal dynamics of the epithelium proliferative activity positively correlates with age-related density fluctuations in lymphocytic infiltration of the glands. Conclusions: We consider that intraepithelial T cells may contribute to the regulation of epithelial cells proliferation in the bulbourethral glands