The magnetic connectivity of coronal shocks from behind-the-limb flares to the visible solar surface during γ\gamma-ray events

Context. The observation of >100 MeV {\gamma}-rays in the minutes to hours following solar flares suggests that high-energy particles interacting in the solar atmosphere can be stored and/or accelerated for long time periods. The occasions when {\gamma}-rays are detected even when the solar eruptions occurred beyond the solar limb as viewed from Earth provide favorable viewing conditions for studying the role of coronal shocks driven by coronal mass ejections (CMEs) in the acceleration of these particles. Aims: In this paper, we investigate the spatial and temporal evolution of the coronal shocks inferred from stereoscopic observations of behind-the-limb flares to determine if they could be the source of the particles producing the {\gamma}-rays. Methods: We analyzed the CMEs and early formation of coronal shocks associated with {\gamma}-ray events measured by the Fermi-Large Area Telescope (LAT) from three eruptions behind the solar limb as viewed from Earth on 2013 Oct. 11, 2014 Jan. 06 and Sep. 01. We used a 3D triangulation technique, based on remote-sensing observations to model the expansion of the CME shocks from above the solar surface to the upper corona. Coupling the expansion model to various models of the coronal magnetic field allowed us to derive the time-dependent distribution of shock Mach numbers and the magnetic connection of particles produced by the shock to the solar surface visible from Earth. Results: The reconstructed shock fronts for the three events became magnetically connected to the visible solar surface after the start of the flare and just before the onset of the >100 MeV {\gamma}-ray emission. The shock surface at these connections also exhibited supercritical Mach numbers required for significant particle energization. [...] (Abridged)Comment: 20 pages, 15 figures, version published in A&

Synchronization in heterogeneous FitzHugh-Nagumo networks with hierarchical architecture

We study synchronization in heterogeneous FitzHugh-Nagumo networks. It is well known that heterogeneities in the nodes hinder synchronization when becoming too large. Here, we develop a controller to counteract the impact of these heterogeneities. We first analyze the stability of the equilibrium point in a ring network of heterogeneous nodes. We then derive a sufficient condition for synchronization in the absence of control. Based on these results we derive the controller providing synchronization for parameter values where synchronization without control is absent. We demonstrate our results in networks with different topologies. Particular attention is given to hierarchical (fractal) topologies, which are relevant for the architecture of the brain

Psychological approach in teaching English

The aspect of foreign language learning is one of the most important issues in TPU since its mission is to increase the competitiveness of the country and provide education of engineering elite by the internalization of the research. Thus the question of the most effective approach in teaching a foreign language becomes vital. Most of the standard methods in teaching a foreign language presented here focus on the analysis, instead we suggest to apply a psychological approach which concentrates on the integrity of the language. Изучение иностранного языка является одним из самых важных вопросов в Томском политехническом университете; его миссия - повышение конкурентоспособности страны и обеспечение подготовки инженерной элиты за счет интернационализации исследований. Так, вопрос поиска наиболее эффективного метода обучения иностранному языку выходит на первое место. Большинство общепринятых методов сконцентрированы на анализе изучаемого материала, разбивающего язык на отдельные аспекты; в данной работе предлагается психологический подход в изучении иностранного языка с акцентом на его целостности

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

Psychological approach in teaching English

The aspect of foreign language learning is one of the most important issues in TPU since its mission is to increase the competitiveness of the country and provide education of engineering elite by the internalization of the research. Thus the question of the most effective approach in teaching a foreign language becomes vital. Most of the standard methods in teaching a foreign language presented here focus on the analysis, instead we suggest to apply a psychological approach which concentrates on the integrity of the language. Изучение иностранного языка является одним из самых важных вопросов в Томском политехническом университете; его миссия - повышение конкурентоспособности страны и обеспечение подготовки инженерной элиты за счет интернационализации исследований. Так, вопрос поиска наиболее эффективного метода обучения иностранному языку выходит на первое место. Большинство общепринятых методов сконцентрированы на анализе изучаемого материала, разбивающего язык на отдельные аспекты; в данной работе предлагается психологический подход в изучении иностранного языка с акцентом на его целостности

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