Generation of the Super Small-Scale Artificial Ionospheric Irregularities in the Ionosphere Pumped by High-Power HF Radio Waves

© 2017, Springer Science+Business Media, LLC, part of Springer Nature. We present the results of experimental studies of generation of super small-scale plasma-density irregularities in the ionospheric F 2 region pumped by a high-power HF O-mode wave at frequencies close to the fourth gyroharmonic in the region of its interaction with the plasma. The experiments were performed using the Sura heating facility. The super small-scale irregularities were sounded by GPS satellite signals. It has been shown that super small-scale irregularities are excited with the most efficiency in the region of the magnetic zenith for the pump wave. The intensity of such irregularities and typical times of their development and decay are determined

Individual insurance products: is there a real choice for Russians?

The article analyzes the level of competition of insurance product offerings in the following four markets using the Russian market as an example: (1) life insurance, (2) accident and disease insurance, (3) voluntary health insurance and (4) pension insurance. The purpose of the study is to assess competitive dynamics in the insurance product markets during the period under review. Relevant data of the Expert Rating Agency for 2018-2021 were used as the study basis. The study methodology is based on the assessment of the competitive situation using the SV matrix, which is based on HTSV (level of differentiation within the dominant group) and CRSV (cumulative market share of the dominant group). The study shows that the Russian insurance market in 2018-2021 was quite diverse in terms of dominance. Most individual insurance products belong to the B4 quadrant of the SV matrix (a natural oligopoly), yet, the situation with the dominant group regarding types of insurance under study is significantly different, since the number of dominant players varies from 2 to 10, considerably affecting a real consumer choice, however, among the markets under study, there is none with low concentration or without a dominant group or dominant leader. In the VHI market, the choice is quite large, while the presence of a big dominant group of eight companies suggests formation of the two-tier companies. The top echelon sets quality standards and dominates by price, while other companies can compete with the leaders due to niche offerings and price factors. The pension insurance market is an example of a significantly reduced consumer choice: in 2018, it is in the RO quadrant with a relatively “weak” dominant group, while by 2021, a hardly differentiated oligopoly of 5 companies has been formed, controlling 95% of the market. Emerging players with the market and institutional opportunities similar to SOGAZ make significant changes in the market structure, as in the case of personal insurance market, wherein SOGAZ has absorbed the largest player, transferring the market from an oligopoly of seven companies to the actual dominance of the one

Results of integrated studies of the perturbed ionosphere region using short-wave ranging in a wide frequency band and stimulated electromagnetic emission of the ionosphere

We present the results of studying simultaneously the dynamics of artificial plasma irregularities in the range of decameter scales l⊥ ≈ 7-125 m being perpendicular to the magnetic field and diagnostic stimulated electromagnetic emission of the ionosphere, which were obtained during heating experiments on the "Sura" facility and several remote points where aspect-scattered signals were received. The daily dependence of the times of evolution and relaxation of the irregularities and the diagnostic emission of the ionosphere are analyzed and compared. © 2012 Springer Science+Business Media, Inc

Generation of Artificial Ionospheric Irregularities in the Midlatitude Ionosphere Modified by High-Power High-Frequency X-Mode Radio Waves

© 2014, Springer Science+Business Media New York. We consider the properties of the artificial ionospheric irregularities excited in the ionospheric F2 region modified by high-power high-frequency X-mode radio waves. It is shown that small-scale (decameter) irregularities are not generated in the midlatitude ionosphere. The intensity of irregularities with the scales l⊥≈50 m to 3 km is severalfold weaker compared with the case where the irregularities are excited by high-power O-mode radio waves. The intensity of the larger-scale irregularities is even stronger attenuated. It is found that the generation of large-scale (l⊥ ≈5–10 km) artificial ionospheric irregularities is enhanced at the edge of the directivity pattern of a beam of high-power radio waves

Impact of a Strong Magnetic Storm and Two X-Ray Flares on the Ionospheric HF Channel in the Summer Solstice of 2015 According to Oblique Sounding in the Eurasian Region

© 2017, Springer Science+Business Media, LLC. We present the results of observations of the impact a strong magnetic storm and two X-ray flares in the summer solstice of 2015 on the HF signal characteristics during oblique sounding of the ionosphere in the Eurasian region. It was found that the negative phase of the magnetic storm led to a strong degradation of the ionospheric channel, up to a long blackout on the paths adjacent to the subauroral latitudes. On the midlatitude paths, a decrease in the maximum observable frequency of the F layer reached 50% with respect to the average values for an undisturbed ionosphere. The propagation velocity of the negative phase of a disturbance from the subauroral to the midlatitude ionosphere is determined (it is equal to about 100 m/s). It is shown that during a magnetic storm the least observable frequency and the average signal-to-noise ratio for the propagation mode via the sporadic E s layer correlate well with the auroral AE index. Anomalous signals were detected in the main phase of the magnetic storm on the Cyprus—Rostov-on-Don path when a chirp ionosonde–radio direction finder was operated in the over-the-horizon HF radar mode. On the basis of modeling and comparison with experimental data, it is shown that the anomalous signals are due to scattering of radio waves by small-scale irregularities located in the subauroral ionospheric F region

Impact of heliogeophysical disturbances on ionospheric HF channels

© 2017 COSPAR. The article presents the results of the observation of a strong magnetic storm and two X-ray flares during the summer solstice in 2015, and their impact on the HF signals characteristics in ionospheric oblique sounding. It was found that the negative phase of the magnetic storm led to a strong degradation of the ionospheric channel, ultimately causing a long blackout on paths adjacent to subauroral latitudes. On mid-latitude paths, the decrease in 1FMOF reached ∼50% relative to the average values for the quiet ionosphere. It is shown that the propagation conditions via the sporadic Es layer during the magnetic storm on a subauroral path are substantially better than those for F-mode propagation via the upper ionosphere. The delay of the sharp decrease in 1FMOF during the main phase of the magnetic storm allowed us to determine the propagation velocity of the negative phase disturbances (∼100. m/s) from subauroral to mid-latitude ionosphere along two paths: Lovozero - Yoshkar-Ola and Cyprus - Nizhny Novgorod. It is shown that both the LOF and the signal/noise ratio averaged over the frequency band corresponding to the propagation mode via the sporadic Es layer correlate well with the auroral AE index. Using an over-the-horizon chirp radar with a bistatic configuration on the Cyprus - Rostov-on-Don path, we located small-scale scattering irregularities responsible for abnormal signals in the region of the equatorial boundary of the auroral oval

Impact of a Strong Magnetic Storm and Two X-Ray Flares on the Ionospheric HF Channel in the Summer Solstice of 2015 According to Oblique Sounding in the Eurasian Region

© 2017 Springer Science+Business Media, LLC We present the results of observations of the impact a strong magnetic storm and two X-ray flares in the summer solstice of 2015 on the HF signal characteristics during oblique sounding of the ionosphere in the Eurasian region. It was found that the negative phase of the magnetic storm led to a strong degradation of the ionospheric channel, up to a long blackout on the paths adjacent to the subauroral latitudes. On the midlatitude paths, a decrease in the maximum observable frequency of the F layer reached 50% with respect to the average values for an undisturbed ionosphere. The propagation velocity of the negative phase of a disturbance from the subauroral to the midlatitude ionosphere is determined (it is equal to about 100 m/s). It is shown that during a magnetic storm the least observable frequency and the average signal-to-noise ratio for the propagation mode via the sporadic E s layer correlate well with the auroral AE index. Anomalous signals were detected in the main phase of the magnetic storm on the Cyprus—Rostov-on-Don path when a chirp ionosonde–radio direction finder was operated in the over-the-horizon HF radar mode. On the basis of modeling and comparison with experimental data, it is shown that the anomalous signals are due to scattering of radio waves by small-scale irregularities located in the subauroral ionospheric F region

Spin physics with antiprotons

New possibilities arising from the availability at GSI of antiproton beams, possibly polarised, are discussed. The investigation of the nucleon structure can be boosted by accessing in Drell-Yan processes experimental asymmetries related to cross-sections in which the parton distribution functions (PDF) only appear, without any contribution from fragmentation functions; such processes are not affected by the chiral suppression of the transversity function $h_1(x)$. Spin asymmetries in hyperon production and Single Spin Asymmetries are discussed as well, together with further items like electric and magnetic nucleonic form factors and open charm production. Counting rates estimations are provided for each physical case. The sketch of a possible experimental apparatus is proposed.Comment: Presented for the proceedings of ASI "Spin and Symmetry", Prague, July 5-10, 2004, to be published in Czech. J. Phys. 55 (2005