Numerical modeling of RadioAstron SRT temperature deformations

The results of modeling the thermal deformations of a space radio telescope’s reflecting surface are presented in the paper. Calculations were performed for the versions of the most unfavorable telescope illumination by the Sun.     

Some additional results in the regular balloon monitoring of cosmic rays in the Earth’s atmosphere

The different types of the data recorded in the experiment of the regular balloon monitoring of cosmic rays (carried out since 1957 by Lebedev Physical Institute, Moscow, Russia, in several locations) are described. So called detailed information (the form of each pulse detected by the ground-based receiver) recorded during the last 12 years is discussed in more details. The use of these data both for getting and correcting the standard results of the experiment and for obtaining some additional information on the cosmic rays in the Earth’s atmosphere is considered.     

Relation between different theories for cosmic ray cross field diffusion

In the past few year several theories have been presented for describing cosmic ray scattering across the mean magnetic field. It is the purpose of the present article to discuss the relation between these different theories in order to improve our understanding of cosmic ray perpendicular scattering and to explore the parameter regimes for which these different theories are valid.     

Missile autopilot design using quasi-LPV polynomial eigenstructure assignment

This paper presents the design of a missile autopilot over its flight envelop using quasi-linear parameter-varying polynomial eigenstructure assignment (PEA). The paper describes the extension of PEA to parameter-varying systems using a nonlinear missile model developed by Horton as an example. The autopilot is designed for a single-plane lateral acceleration control and a 5 degree of freedom (DOF) autopilot is also designed. Both lateral acceleration and augmented lateral acceleration outputs are considered. The lateral acceleration autopilot has nonminimum phase characteristics, and it is shown that the quasi-linear parameter-varying PEA approach can handle nonminimum phase systems unlike classic dynamic inversion techniques. Simulation results are presented over fast variations in Mach number and show that the design is robust.     

Statistical study of interplanetary condition effect on geomagnetic storms

Based on the archive OMNI data for the period 1976–2000 an analysis has been made of 798 geomagnetic storms with D _st < −50 nT and their interplanetary sources-large-scale types of the solar wind: CIR (145 magnetic storms), Sheath (96), magnetic clouds MC (62), and Ejecta (161). The remaining 334 magnetic storms have no well-defined sources. For the analysis, we applied the double method of superposed epoch analysis in which the instants of the magnetic storm beginning and minimum of D _st index are taken as reference times. The well-known fact that, independent of the interplanetary source type, the magnetic storm begins in 1–2 h after a southward turn of the IMF (B _z < 0) and both the end of the main phase of a storm and the beginning of its recovery phase are observed in 1–2 h after disappearance of the southward component of the IMF is confirmed. Also confirmed is the result obtained previously that the most efficient generation of magnetic storms is observed for Sheath before MC. On the average parameters B _z and E _y slightly vary between the beginning and end of the main phase of storms (minimum of D _st and D _st ^* indices), while D _st and D _st ^* indices decrease monotonically proportionally to integral of B _z and E _y over time. Such a behavior of the indices indicates that the used double method of superposed epoch analysis can be successfully applied in order to study dynamics of the parameters on the main phase of magnetic storms having different duration.     

New estimates of ionization potentials of four DIB molecular carriers.

We present a study of the behaviour and ionization properties of four Diffuse Interstellar Bands (DIBs) at lambda lambda 5780, 5797, 6379 and 6613 angstroms. In the lambda lambda 5797, 6379 and 6613 angstrom DIBs, substructures have recently been detected, indicating large gaseous molecular carriers. Studying DIBs in regions with different physical properties in terms of UV flux and density enables us to monitor the behaviour of the carriers and hence to constrain their nature. As a follow-up of Sonnentrucker et al. (1997), we add new lines of sight and generalize the results for lines of sight with 2 or 3 clouds. This refines the Ionization Potential estimates which are between 10 and 13 eV, hence reminiscent of PAH or fullerene cations for those DIBs.     

Concentration of ions in the topside ionosphere as measured onboard the <Emphasis Type="Italic">DEMETER</Emphasis> satellite: Morphology and dependence on solar and geomagnetic activity

Variations in concentration of ions H⁺, He⁺, and O⁺ are studied at a height of about 700 km using the data of continuous observations onboard the DEMETER satellite at the decline and in the minimum of solar activity from 2004 to 2008. Latitudinal distributions, seasonal behavior, and irregular variations in ion concentrations and their dependence on solar and geomagnetic activity are considered. Within this altitude range, for the first time an analysis is performed of the dataset of many-year continuous observations in both hemispheres from the equatorial to subauroral latitudes. This made it possible to describe the seasonal and irregular variations of the concentrations of main ion species with better time and spatial resolution than in the available empirical models. The dependence of concentrations of three types of ions on solar and geomagnetic activity is studied at time scales from several days to several years, and it is shown that the anti-phase change in concentrations of O⁺ and light ions known from publications is partly a result of mutual dependence of solar and geomagnetic activity and is observed only at time scales beginning from several months. At time scales from several days to several weeks, variations in the concentration of O⁺ and light ions are governed mainly by solar and geomagnetic activity, respectively.     

Diffusion coefficients of multicomponent combustion product mixture

The behavior of generalized diffusion coefficients and diffusion flows of individual substances in the multicomponent gas mixture is investigated. The combustion products of liquid rocket propellants being used are considered.     

Solar Isotopic Composition as Determined Using Solar Energetic Particles

Solar energetic particles (SEPs) provide a sample of the Sun from which solar composition may be determined. Using high-resolution measurements from the Solar Isotope Spectrometer (SIS) onboard NASA’s Advanced Composition Explorer (ACE) spacecraft, we have studied the isotopic composition of SEPs at energies ≥20 MeV/nucleon in large SEP events. We present SEP isotope measurements of C, O, Ne, Mg, Si, S, Ar, Ca, Fe, and Ni made in 49 large events from late 1997 to the present. The isotopic composition is highly variable from one SEP event to another due to variations in seed particle composition or due to mass fractionation that occurs during the acceleration and/or transport of these particles. We show that various isotopic and elemental enhancements are correlated with each other, discuss the empirical corrections used to account for the compositional variability, and obtain estimated solar isotopic abundances. We compare the solar values and their uncertainties inferred from SEPs with solar wind and other solar system abundances and find generally good agreement.     

On improvement of materials separation accuracy by superimposition of electric fields

In this paper, the existing techniques of electrochemical dimensional machining are considered. The use of an additional current-conducting template makes it possible to improve the accuracy of materials separation with the aid of the electric field superimposed.