The shock-acoustic waves generated by earthquakes

We investigate the form and dynamics of shock-acoustic waves generated by earthquakes. We use the method for detecting and locating the sources of ionospheric impulsive disturbances, based on using data from a global network of receivers of the GPS navigation system and requiring no a priori information about the place and time of associated effects. The practical implementation of the method is illustrated by a case study of earthquake effects in Turkey (August 17, and November 12, 1999), in Southern Sumatera (June 4, 2000), and off the coast of Central America (January 13, 2001). It was found that in all instances the time period of the ionospheric response is 180-390 s, and the amplitude exceeds by a factor of two as a minimum the standard deviation of background fluctuations in total electron content in this range of periods under quiet and moderate geomagnetic conditions. The elevation of the wave vector varies through a range of 20-44 degree, and the phase velocity (1100-1300 m/s) approaches the sound velocity at the heights of the ionospheric F-region maximum. The calculated (by neglecting refraction corrections) location of the source roughly corresponds to the earthquake epicenter. Our data are consistent with the present views that shock-acoustic waves are caused by a piston-like movement of the Earth surface in the zone of an earthquake epicenter.Comment: EmTeX-386, 30 pages, 4 figures, 3 tabl

Overview of V.A. Plotnikov’s research on averaging of differential inclusions

In this review, we will first look in detail at Plotnikov’s results on the substantiation of full and partial schemes of averaging of differential inclusions of the standard form on finite and infinite intervals. Then we will consider the algorithms where it is not possible to find the average, but there is a possibility to find its estimation from below and from above. Such an approach is also used when the average can be found only approximately. This situation is common for differential inclusions with fast and slow variables. In the end, we will present the results on the substantiation of the full and partial averaging methods for impulsive differential inclusions on finite and infinite intervals

Enhancement of construction of water chambers of network water heaters of steam turbine for combined heat and energy production

The report explores the possibility of using partitions of network heater chambers as anchor ties and examples of their design are presented. The results of calculations of such chambers are presented. Based on the results of these calculations, it is concluded that using the anchor partitions makes it possible to significantly reduce bending stresses in the bottom and tube plate, reduce the load on the flange connection, use a flat bottom instead of the elliptical one, significantly reduce the longitudinal stresses in the tubes, which increases the life of the most damageable heater element.В докладе рассматривается возможность использования перегородок водяных камер сетевых подогревателей в качестве анкерных связей и примеры их конструктивного исполнения. Приводятся результаты расчетов таких камер. По результатам этих расчетов сделаны выводы, что использование анкерных перегородок позволяет существенно уменьшить изгибные напряжения в днище и трубной доске, уменьшить нагрузку на фланцевое соединение, вместо эллиптического днища использовать плоское, существенно уменьшить продольные напряжения в трубках, что повышает ресурс самого повреждаемого элемента подогревателя

Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona

The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow solar wind forms. To this end, we have carried out a multipoint analysis of small transient structures released from a north-south tilted helmet streamer into the slow solar wind over a broad range of position angles during Carrington Rotation 2137. Combining the remote-sensing observations taken by the Solar-TErrestrial RElations Observatory (STEREO) mission with coronagraphic observations from the SOlar and Heliospheric Observatory (SOHO) spacecraft, we show that the release of such small transient structures (often called blobs), which subsequently move away from the Sun, is associated with the concomitant formation of transient structures collapsing back toward the Sun; the latter have been referred to by previous authors as "raining inflows." This is the first direct association between outflowing blobs and raining inflows, which locates the formation of blobs above the helmet streamers and gives strong support that the blobs are released by magnetic reconnection.Peer reviewe

Stationary Flows of the Parabolic Potential Barrier in Two Dimensions

In the two-dimensional isotropic parabolic potential barrier $V(x, y)=V_0 -m\gamma^2 (x^2+y^2)/2$, though it is a model of an unstable system in quantum mechanics, we can obtain the stationary states corresponding to the real energy eigenvalue $V_0$. Further, they are infinitely degenerate. For the first few eigenstates, we will find the stationary flows round a right angle that are expressed by the complex velocity potentials $W=\pm\gamma z^2/2$.Comment: 12 pages, AmS-LaTeX, 4 figure

Continuous Monitoring of Information on Anode Current Distribution as Means of Improving the Process of Controlling and Forecasting Process Disturbances

За последние десятилетия система АСУТП электролиза достигла больших возможностей по улучшению сбора и обработки сигналов, которые обеспечивают основу для регулирования питания, теплового баланса и магнитогидродинамической (МГД) стабильности. Несмотря на значительное развитие, постоянно растут потребности в датчиках контроля, которые могут распознавать и реагировать на возникающие изменения. C 2008 г. на электролизерах опытного участка РА-400, расположенного в опытно-промышленном корпусе электролиза ОАО «РУСАЛ Саяногорск», эксплуатируется система непрерывного мониторинга информации о распределении тока по анодам, интегрированная в АСУТП СААТ-2. На протяжении промышленных испытаний система мониторинга постоянно совершенствовалась в части достоверности информации, обеспечения работоспособности оборудования в условиях агрессивных сред, а также при выполнении технологических и ремонтных операций на электролизере. Полученная информация о распределении тока по анодам позволила разработать алгоритмы, прогнозирующие на ранней стадии отклонения в питании глиноземом электролизера с последующим перераспределением по точкам автоматической подачи глинозема (АПГ), прогнозирование и распознавание технологических нарушений на подошве анодов («конуса»)The aluminum reduction process control system in recent decades has given great opportunities for improving the collection and processing of signals that provide the basis for the adjustment of feeding, thermal balance and magnetohydrodynamic (MHD) stability. Despite considerable development, there is a growing need for control sensors that can detect and respond to emerging changes. Since 2008, the cells operating in the RA-400 pilot area inside the Pilot Potroom at OJSC RUSAL Sayanogorsk have been using a system for continuous monitoring of information on anode current distribution. The system has been integrated in the ‘CAAT-2’ control system. In the course of industrial tests, the monitoring system was continuously improved – in terms of information reliability, and equipment operability in aggressive environments and during pot tending & maintenance operations. The obtained information on anode current distribution allowed for developing algorithms to detect, at an early stage, variations in cell alumina feeding, including further alumina re-distribution between feed points, and forecast and detect anode bottom problems (“spike”

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Development of Internal Control System in the Modern Companies: Theoretical Approaches and Suggestions for Improvement

Complication of a competitive situation forces the modern companies to pay special attention to the organization of management. Most it belongs to the companies, which conduct economic activity in the cross border mode, for example to the companies of the oil and gas sector. One of ways of increase in efficiency of management is development of such element as a subsystem of internal control. The research objective consists in the analysis of conditions and prerequisites of the organization of internal control in the company and development of recommendations about its implementation. Research problems are assessment of the importance of internal control for effective management of the companies; identification of conditions and restrictions of development of internal control systems of the Russian companies; the analysis of advantages of use of internal control system in the company; justification of recommendations about development of internal control system. Because of the conducted research, it is revealed that influence formation of internal control systems of the modern Russian companies as factors of national and international property. At the same time complication of a political and economic situation in the world and aggravation of sanctions and information confrontation between the countries of the world results in need of account for the organization of systems of management in general and subsystems of internal control in particular of the international requirements. Recommendations about development of internal control systems of the Russian organizations based on the Concept of COSO are presented in the article. Practical use of results of the conducted research is possible in the systems of management of the Russian companies including relating to the oil and gas sector

Choice of parameters and stability of nonlinear vibration isolation device

Work of active vibration isolation devices with single-mass electromagnetic suspension taking into account of real characteristics of the voltage regulators is described. The analytical researches are carried out; the areas of stability of work of nonlinear vibration isolation device are defined