Determination of the threshold value of F10.7 in the dependence of foF2 on solar activity

By introducing the two-segmented linear regression model instead of the well known quadratic fit, we were able to describe the solar activity dependence of the F2 critical frequency. Saturation features were observed and the corresponding F10.7 values at which this phenomenon occurs were obtained for different hours. The seasonal average values were found to be around 154 sfu, 138 sfu, 177 sfu and 150 sfu for March equinox, June solstice, September equinox and December solstice respectively. These affirmed that saturation phenomenon is more pronounced at the equinoxes than solstices. On the average, the threshold value of F10.7 was obtained to be 154.5 sfu for this station in the African sector of the equatorial region.     

TEC derived from some GPS stations in Nigeria and comparison with the IRI and NeQuick models

Total electron content (TEC) measured simultaneously using Global Positioning System (GPS) ionospheric monitors installed at some locations in Nigeria during the year 2011 (Rz = 55.7) was used to study the diurnal, seasonal, and annual TEC variations. The TEC exhibits daytime maximum, seasonal variation and semiannual variations. Measured TEC were compared with those predicted by the improved versions of the International Reference Ionosphere (IRI) and NeQuick models. The models followed the diurnal and seasonal variation patterns of the observed values of TEC. However, IRI model produced better estimates of TEC than NeQuick at all locations.     

High-Precision Space Astrometry of Gamma-Ray Bursts: II. Relativistic Corrections in Converting the Time Scales

A technique for the determination of cosmic gamma-ray burst coordinates by measuring the time lag between gamma-ray burst signals on different spacecraft in the near-Sun orbits is developed. On the basis of the well-known relativistic time transformation between barycentric, geocentric, and instrumental coordinate frames of reference, the time corrections for specific spacecraft systems are calculated. Among various relativistic corrections, those are determined that are significant for the method in question.     

Method and Results of Direct Measurement of the Interstellar Neutral Helium Abundance and Isotopic Composition

One of the important astrophysical problems is the determination of the abundance of helium isotopes ³He and ⁴He in different regions of the Universe, because this abundance can reflect its history by pointing to the intensity of various possible processes of the creation and decay of light elements. This paper describes the method and results of the determination (for the first time performed by a direct method) of the helium isotopic abundance in the local interstellar medium surrounding the Solar system. The experiment was carried out on the manned Mir space station by long-term space exposure of samples of metal foil with their subsequent recovery to the Earth and detailed laboratory mass-spectrometric analysis. As a result, we succeeded in obtaining an estimation of the ⁴He concentration (about 7.5 × 10^–3 cm^–3) and the isotopic ratio ³He/⁴He (about1.7 × 10^–4) for the local interstellar medium.     

Investigations of the Background Stratospheric Aerosol Using Multicolor Wide-Angle Measurements of the Twilight Glow Background

The first results of multiwave measurements of twilight background and the all-sky camera with a color (RGB) CCD matrix conducted in the spring and summer of 2016 in Central Russia (55.2° N, 37.5° E) have been discussed. The observations reveal the effect of aerosol scattering at heights of up to 35 km, which is substantially enhanced in the long-wave part of the spectrum (R band with an effective wavelength of 624 nm). An analysis of the behavior of the sky color during light period of twilight with allowance for the absorption by ozone in the Chappuis bands make it possible to restore the angular dependences of the intensity of the aerosol scattering of the light. This is used to determine the parameters of the lognormal distribution of aerosol particles over their sizes with a mean radius of 0.08 μm and a width of 1.5–1.6 for the stratospheric height interval.     

空间温室灯组件的自适应控制

到目前为止,基于发光二极管(Light Emitting Diodes-based,LED)的照明器被广泛用于除自然光之外的温室植物照明,以及没有自然光的植物工厂.优化人工光照参数,如日光照积分和不同光谱成分的比值,可以显著降低生物生命支持系统(Biological Life Support Systems,BLSS)...     

From the Solar Wind to the Magnetospheric Substorm

This paper gives a brief outline of the progression from the first substorm model developed in Ref.[4] and[8] based on Kennel's ideas[3], to the present views about the mechanism by which solar wind kinetic energy is converted to electromagnetic energy at the Bow Shock and by which this energy is transferred to the magnetosphere in the form of current; about the transformation of the energy of this current to gas kinetic energy of convecting plasma tubes, and, finally, the back transformation of gas kinetic energy to electromagnetic energy in secondary magnetospheric MHD generators. The questions of the formation of the magnetospheric convection system, the nature of substorm break-up, and of the matching of currents in the magnetosphere-ionosphere system are discussed.      

Education programme on aerospace and environmental medicine for medical faculty of Lomonosov Moscow State University.

The problems and approaches to organisation of the education process in the field of aerospace and environmental medicine for medical students are discussed. Original education developed on the basis of Russian experience in space biology and physiology, environmental medicine, aerospace medicine and medical support during spaceflight. The main goals of these programs are to acquaint students with: interaction of living organisms with natural and artificial surroundings, including space flight conditions; the physiological reactions on extreme environmental factors; basic mechanisms of human adaptation to space flight and particularly to microgravity; the current research in space medicine and new telecommunication technologies. All programs are formed in accordance with contemporary progress in life sciences and revealed a result of the interdisciplinary approach to education process.     

Distribution of energetic particles and secondary radiation according to orbital station “MIR” data obtained in 1991

A set of instruments for measuring energetic particle fluxes, containing two neutron detectors under different plexiglas shielding thicknesses, a scintillation detector, measuring energy release >0. I MeV and 0.5 MeV and a Geiger counter were launched onboard OS ‘MIR’. The latitude dependencies of the cosmic ray measurements were obtained and studied. The distributions of primary particle fluxes (protons and electrons) as well as secondary particle fluxes (bremsstrahlung gamma-rays and neutrons) produced in interactions of radiation belt particles with the station materials were obtained. The electron belt, generated during the storm of March 24 1991, is studied.