Superradiance or total reflection?

Numerical evolution of massless scalar fields on Kerr background is studied. The initial data specifications are chosen to have compact support separated from the ergoregion and to yield nearly monochromatic incident wave packets. The initial data is also tuned to maximize the effect of superradiance. Evidences are shown indicating that instead of the anticipated energy extraction from black hole the incident radiation fail to reach the ergoregion rather it suffers a nearly perfect reflection.Comment: 8 pages, 6 figures, contribution to the proceedings of the conference on Relativity and Gravitation: 100 Years after Einstein in Pragu

TRANSIENT STABILITY IMPROVEMENT OF EHV POWER TRANSMISSIONS BY ADAPTIVE SINGLE-POLE RECLOSING

Some special aspects of the stability properties of EHV power transmissions are pointed out in the introduction, followed by a more detailed analysis of the impact of single-pole short circuits and automatic reclosing. Digital investigation results are described, on ground of which critical reclosing dead-time values are established in function of the pretransient power transfer and other relevant parameters. The advantages of adaptive single-pole reclosing method are stressed for increasing the chances of preserving synchronism, and "probability of transient stability" values calculated, which clearly show the favorable effects of said method on the transient stability levels of EHV transmissions

Orbán's Invincibility is Over: Municipal Elections in Hungary

Regional elections were held in Hungary on October 13, 2019. Viktor Orbán’s Fidesz party preserved its dominance over regional assemblies as well as most rural towns and villages. Meanwhile, a united opposition managed to take control of 10 of 23 Hungarian cities, including 14 of 23 districts in Budapest – enabling it to determine the capital’s lord mayor. Although these developments mark the end of Orbán’s decade-long invincibility, they do not necessarily pave the way to opposition success in national elections scheduled for 2022