Simultaneous observations of the 557.7 nm airglow and stimulated electromagnetic emission during HF pumping of the ionosphere with diagnostic schedule: First results

The first results on simultaneous observation for artificial airglow emission at 557.7 nm (green line) and stimulated electromagnetic emission (SEE) during HF pumping of the ionosphere with specially designed HF pulsing sequence are reported. Ionospheric radio pumping was performed at the "Sura" radio facility situated near Niznhny Novgord, Russia. The measurements of airglow were handled at the Astronomical Observatory of Kazan State University (220 km to the east of "Sura" facility) by the astronomical telescope AZT-14 connected with the electric photometer. During several "Sura" runs enhancements of the airglow intensity in time with pump wave pulses were observed after the pump wave switch from continuous transmission to low duty cycle pulse transmission. The airglow and SEE intensities and SEE decay rates were correlated. © 2004 COSPAR. Published by Elsevier Ltd. All rights reserved

Studies of artificial airglow emission at 557.7 nm (green line) of upper atmosphere caused by "Sura" facility

Some experimental results of artificial airglow emission at 557.7 nm (green line) during HF pumping of the ionosphere with specially designed HF pulsing sequence are reported. Ionospheric radio pumping was performed at the "Sura" radio facility situated near Niznhny Novgord, Russia. The measurements of airglow were handled at the Astronomical Observatory of Kazan State University (220 km to the east of "Sura" facility) by the astronomical telescope AZT-14 connected with the electric photometer. During several "Sura" runs enhancements of the airglow intensity in time with pump wave pulses were observed after the pump wave switch from continuous transmission to low duty cycle pulse transmission

Propagation of HF radio waves over northerly paths: measurements,simulation and systems aspects

Large deviations in the direction of arrival of ionospherically propagating radio signals from the Great Circle Path (GCP) have serious implications for the planning and operation of communications and radiolocation systems operating within the HF-band. Very large deviations are particularly prevalent in the polar and sub-auroral regions where signals often arrive at the receiver with bearings displaced from the great circle direction by up to ±100° or more. Measurements made over several paths are presented in this paper, and the principle causes of off-great circle propagation outlined. Significant progress has been made in modelling the propagation effects and work is now in hand to incorporate the results into tools to aid the planning and operation of HF radio systems operating at northerly latitudes

The measurement of the ionospheric total content variations caused by a powerful radio emission of "sura" facility on a network of GNSS-receivers

© 2015 COSPAR. Published by Elsevier Ltd. All rights reserved.Observations of the perturbations of total electron content (TEC) caused by a powerful radio emission of "Sura" facility (Radio Physical Research Institute, N. Novgorod) were carried out during several experimental campaigns from March of 2010 to March 2013. In this paper the data of experimental measurements of TEC-variations conducted on March, 15, 2010 and on March, 12, 2013, are presented. Parameters of TEC-variations were obtained by dual-frequency global navigation satellite systems (GNSS) diagnostics. Registration of signal parameters from GNSS-transmitters was performed at spatially separated sites along the geomagnetic latitude: Vasilsursk (56°08′N, 46°05′ E), Zelenodolsk (55°52′N, 48°33′E) and Kazan (55°48′N, 49°08′E). In the experiments radio path from GNSS satellite to Vasilsursk passed over the disturbed region of ionosphere, but radio paths to Zelenodolsk and to Kazan did not. However, TEC-variations correlated with pumping of ionosphere by "Sura" facility were detected for all up to three ground measurements sites. Magnitudes of TEC-variations reached up to ∼0.6-0.7 TECU. The speculation that a sharp gradient of the electron density formed at the border of the main lobe of "Sura" facility may cause the generation of IGW is presented

Dynamics of large-scale ionospheric inhomogeneities caused by a powerful radio emission of the Sura facility from the data collected onto ground-based GNSS network

© 2017, Pleiades Publishing, Ltd.The measurements of variations in the total electron content of the Earth’s ionosphere along the GPS satellite signal propagation path are described. The signal parameters were measured at a network of receivers at three distant sites: Sura (Vasilsursk), Zelenodolsk, and Kazan. They are arranged along the geomagnetic latitude of the Sura Facility under short-wave radio irradiation of the ionosphere. One feature of the experiment is the crossing of a disturbed region by the radio path between a GPS satellite and Vasilsursk. This resulted from the angular sizes of the Sura array pattern; the radio paths between a GPS satellite and Zelenodolsk and a GPS satellite and Kazan did not cross. Variations in the total electron content of up to 0.15−0.3 TECU were revealed at all three sites during four experimental campaigns (March 2010, March 2013, May 2013, and November 2013). The lateral scale of an ionospheric disturbance stimulated by a high-power radio wave and the velocity of its west-to-east propagation along the geomagnetic latitude were 30–60 km and 270–350 m/s, respectively. A decrease in the total electron content (down to 0.55 TECU) was recorded along the Kazan–Zelenodolsk–Vasilsurks line, which is connected with the solar terminator transit; the lateral scale of the related ionospheric inhomogeneities was ~65–80 km

The 630 nm and 557.7 nm Airglow During HF Ionosphere Pumping by the SURA Facility Radiation for Pump Frequencies Near the Fourth Electron Gyroharmonic

© 2015, Springer Science+Business Media New York. We present the results of analysis of the dependence of the ionospheric airglow in the red (630 nm) and green (557.7 nm) lines of atomic oxygen on the pump-wave frequency f0 near the fourth electron gyroharmonic 4fce. The experimental data were obtained in 2012 using the SURA heating facility. Stimulated electromagnetic emission spectra were used to determine the relation between f0 and 4fce. It is found that at f0 > 4fce and δf = f0 − 4fce ≈ 15–20 kHz the red-line airglow intensity is about a factor of 1.5 higher for the magnetic zenith pumping (when the pump beam is inclined 12° south of the magnetic field direction) than for the vertical pumping. In the green line for the same offsets δf, the airglow was recorded with confidence only during magnetic zenith pumping. During vertical pumping, no regular dependence of the red-line airglow intensity on δf in the range −15 < δf < 280 kHz was obtained, while the green-line airglow was observed at 15 < δf < +5 kHz and 230 < δf < 280 kHz. In the red line during vertical pumping, a change from the artificial airglow generation to the ionospheric background suppression was detected when the F-layer cutoff frequency was decreased. During magnetic zenith pumping, a wide (about 30°) background suppression zone was observed around the airglow spot with an about 6° angular width

Farit Gabidinovich Avkhadiev (on his 70th birthday)

This article about mathematical results of F.G. Avkhadiev

РОЛЬ ВИРУСНЫХ ИНФЕКЦИЙ В РАЗВИТИИ ХРОНИЧЕСКИХ ЭЗОФАГИТОВ У ДЕТЕЙ

The aim of this study was to reveal features of chronic viral esophagitis in children. 102 patients from 3 till 17 years with histologically confirmed chronic esophagitis (CE) are surveyed. Immunohistochemically viruses have been found in esophageal mucosa in 65 (64 %) children (1 group). 37 children (2 group) have CE of other causes. In 50 (77 %) children of 1 group HV have been revealed, in 22 (34 %) - CMV, in 19 (29 %) - VEB, in 22 (34 %) a combination of 2 or 3 viruses. Clinical manifestation of viral esophagitis was similar to reflux-esophagitis. Endoscopical signs of CE have been found in 55 % of children of 1 group and in 40,5% of 2 group, erosions were only in 1 group (15 %). The inflammatory index in 1 group was significantly higher, diskeratosis (14 %), parakeratosis (6 %) and balloon dystrophy (32 %) of esophageal epithelium were also revealed in it, but columnar metaplasia was not found. Thus, we have revealed high frequency of chronic virus infection as the cause of CE in immunocompetent patients. Erosions, higher degree of inflammatory changes morphologically and more manifest clinical symptoms are typical for a chronic virus esophagitis.Целью работы было выявить особенности вирусных эзофагитов у детей. Обследованы 102 пациента от 3 до 17 лет с гистологически установленным хроническим эзофагитом (ХЭ). Иммуногистохимически вирусы в слизистой оболочке пищевода (СОП) выявлены у 65 (64%) детей (1-я группа). 2-ю группу составили дети с ХЭ другой этиологии. У 50 (77%) детей 1-й группы выявлен ВПГ, у 22 (34%) – ЦМВ, у 19 (29%) – ВЭБ, из них у 22 (34%) пациентов было сочетание 2 или 3 вирусов. Балльная оценка жалоб показала, что клиническая симптоматика при вирусных эзофагитах неспецифична и сходна с таковой при ГЭРБ. Эндоскопически ХЭ выявлен у 55% детей в 1-й группе и у 40,5% – во 2-й, эрозивный ХЭ – только в 1-й группе (15%). Воспалительный индекс (ВИ) в 1-й группе был достоверно выше, выявлены дискератоз (14%), паракератоз (6%), баллонная дистрофия (32%) плоского эпителия, желудочная метаплазия не обнаружена. Таким образом, мы выявили высокую частоту хронической вирусной инфекции как причины развития ХЭ у иммунокомпетентных пациентов. Для хронической вирусной инфекции характерны эрозивные формы эзофагита, более высокая степень воспалительных изменений при морфологическом исследовании и более яркие клинические проявления

Fragmentation and Multifragmentation of 10.6A GeV Gold Nuclei

We present the results of a study performed on the interactions of 10.6A GeV gold nuclei in nuclear emulsions. In a minimum bias sample of 1311 interac- tions, 5260 helium nuclei and 2622 heavy fragments were observed as Au projec- tile fragments. The experimental data are analyzed with particular emphasis of target separation interactions in emulsions and study of criticalexponents. Multiplicity distributions of the fast-moving projectile fragments are inves- tigated. Charged fragment moments, conditional moments as well as two and three -body asymmetries of the fast moving projectile particles are determined in terms of the total charge remaining bound in the multiply charged projectile fragments. Some differences in the average yields of helium nuclei and heavier fragments are observed, which may be attributed to a target effect. However, two and three-body asymmetries and conditional moments indicate that the breakup mechanism of the projectile seems to be independent of target mass. We looked for evidence of critical point observable in finite nuclei by study the resulting charged fragments distributions. We have obtained the values for the critical exponents gamma, beta and tau and compare our results with those at lower energy experiment (1.0A GeV data). The values suggest that a phase transition like behavior, is observed.Comment: latex, revtex, 28 pages, 12 figures, 3tables, submitted to Europysics Journal