Looking to Each Other: Russian-European Relations among Hostility and Fear

The article deals about the historical relation between Tsarist Russia/USSR and Western Europe/Integrated Europe. Since the beginning of the European construction process, by focusing on the ideological prophecies of capitalist contradictions, communist authorities did not understand the potential significance of the efforts of people like Jean Monnet, directed at economic, financial, and cultural integration. Although the Soviet bloc economy needed economic relations with Western Europe, its political rulers rejected the idea of any European federation or confederation on the old continent. Even before the birth of the Soviet Union, Europe and Russia had always looked to each other with diffidence or fear. Specifically, the geographical and identity location of Russia has always suffered because of the ambiguity of being a border between East and West, between Asia and Europe. Nevertheless, it would be misleading to measure the Russian swing between East and West by the yardstick of its greater or lesser Europeanization: this view would presuppose an implicit hierarchical relationship between Europe and Russia, of which historians should \u201cestimate\u201d progress or involution taking \u201cRussia\u2019s Europeanisation\u201d as a single unit of measure. On the contrary, the relationship between Europe \u2013 understood in different historical moments as a geographical reality and/or as European Community/Union \u2013 and Russia has from time to time been expressed by the Russians in a complex reception of European or non-European models. Moreover, Russia looks at this relationship with the ambition to be an autonomous driving force because of belief to identify itself as the center of the world and not as a periphery. So it is important to analyzes how Western Europe and Russia, being located within a common geographical area, have historically created a web of relationships characterized by attraction and repulsion, conditioned for centuries by ideology and power logic and often degenerated into contradictions and incompatibility

Dry galloping in inclined cables: linear stability analysis

Abstract In the last decade, dry galloping has been frequently observed on real stay cables also in the case of circular cross section. It is an aeroelastic phenomenon which occurs when structures or structural elements are generically placed with respect to the wind, being both incidence and yaw angles different from zero. Here, after writing down the equations which describe the static reference configuration of an inclined cable under the self-weight, the equations of motion are obtained up to third order, where the forces related to the wind are evaluated coherently with an aerodynamic model, drawn under the quasi-steady hypothesis. A Galerkin projection is carried out and the critical conditions causing Hopf bifurcation on the trivial equilibium configuration are then evaluated

Postcritical Behavior of Cables Undergoing Two Simultaneous Galloping Modes

A nonlinear two degree-of-freedom model, describing a flexible elastic suspended cable undergoing galloping oscillations, is analyzed. By using a perturbative approach, the critical conditions occuring for different values of the aerodynamic coefficients are described. Two different type of critical conditions, corresponding to simple or double Hopf bifurcations are found. The nonlinear postcritical behavior of single taut strings in 1:1 primary internal resonance is studied through the multiple scale perturbation method. In the double Hopf bifurcation case the influence of the detuning between the critical eigenvalues on the postcritical behavior is illustrated. It is found that quasi-periodic motions, which are likely to occur in the linear field when the two critical frequencies are incommensurable, are really unstable in the nonlinear range. Therefore, the postcritical behavior of the string consists of stable periodic motions for any detuning values

An OSRC Preconditioner for the EFIE

The Electric Field Integral Equation (EFIE) is a well-established tool to solve electromagnetic scattering problems. However, the development of efficient and easy to implement preconditioners remains an active research area. In recent years, operator preconditioning approaches have become popular for the EFIE, where the electric field boundary integral operator is regularised by multiplication with another convenient operator. A particularly intriguing choice is the exact Magnetic-to-Electric (MtE) operator as regulariser. But, evaluating this operator is as expensive as solving the original EFIE. In work by El Bouajaji, Antoine and Geuzaine, approximate local Magnetic-to-Electric surface operators for the time-harmonic Maxwell equation were proposed. These can be efficiently evaluated through the solution of sparse problems. This paper demonstrates the preconditioning properties of these approximate MtE operators for the EFIE. The implementation is described and a number of numerical comparisons against other preconditioning techniques for the EFIE are presented to demonstrate the effectiveness of this new technique