Anthropogenic Space Weather

Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release ex- periments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure

Sources of Investment Support of Production and Business Activities in the Russian Economy

The problems of determining effective and available sources of investment for the purposes of technical and organizational development of enterprises and business activities are studied. An urgent requirement is to reverse the unstable dynamics of the industrial investments volumes implemented by Russian enterprises, the low degree of renewal of fixed assets of enterprises that go to a critically high level of wear and tear, which does not allow for high resource productivity and competitiveness of Russian enterprises of processing activities in the world market. The purpose of the study is to consider the indicators of the current state and the possibility of using certain available sources of investment in production, to analyze the characteristics of state regulation of investment activity in the economy. The article uses methods of statistical grouping, analysis of cause-and-effect relations, and meaningful economic interpretation of the phenomena of the investment process in the Russian and world economy conditions. A comparative analysis of the most popular sources of investment support for production and economic activities of enterprises is carried out, their advantages and disadvantages, and features of use are shown. As a result, recommendations were formed on the choice of investment sources in relation to various economically stable groups of manufacturing enterprises operating in markets of different regulatory severity

Orbitally induced hierarchy of exchange interactions in zigzag antiferromagnetic state of honeycomb silver delafossite Ag3Co2SbO6

We report the revised crystal structure, static and dynamic magnetic properties of quasi-two dimensional honeycomb lattice silver delafossite Ag3Co2SbO6. The magnetic susceptibility and specific heat data are consistent with the onset of antiferromagnetic long range order at low temperatures with Néel temperature TN ~ 21.2 K. In addition, the magnetization curves revealed a field-induced (spin-flop type) transition below TN in moderate magnetic fields. The GGA+U calculations show the importance of the orbital degrees of freedom, which maintain a hierarchy of exchange interaction in the system. The strongest antiferromagnetic exchange coupling was found in the shortest Co-Co pairs and is due to direct and superexchange interaction between the half-filled xz+yz orbitals pointing directly to each other. The other four out of six nearest neighbor exchanges within the cobalt hexagon are suppressed, since for these bonds active half-filled orbitals turned out to be parallel and do not overlap. The electron spin resonance (ESR) spectra reveal a broad absorption line attributed to Co2+ ion in octahedral coordination with average effective g-factor g=2.40±0.05 at room temperature and show strong divergence of ESR parameters below ~ 150 K, which implies an extended region of short-range correlations. Based on the results of magnetic and thermodynamic studies in applied fields, we propose the magnetic phase diagram for the new honeycomb-lattice delafossite