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The possibility of the existence of radiation belts near a planet possessing an intrinsic magnetic field and located in a stellar plasma flow is considered using Mercury as an example. An analysis is performed both using Stormer’s theory of charged particle motion, in which not the specific trajectories of individual particles, but the regions of allowed motion in an axisymmetric field are considered, and by analyzing the trajectories. The existence of trapped radiation near Mercury is shown to be possible, and the criteria for the formation of a stable population of trapped particles are formulated.

The paper considers the classification of solar wind streams in magnetohydrodynamic parameters (MHD-types); combinations of proton speed, density, temperature, and magnetic field strength, in addition to the classical solar wind separation into high-speed streams from coronal holes, transient streams of coronal mass ejections, and the slow solar wind from the streamer belt. Two classifications of solar wind properties were compared for the events in August 2010 and May 2011, when one could observe the interaction of two coronal mass ejections and a coronal mass ejection with a high-speed solar wind stream from the coronal hole, respectively. It is shown that the classical description of a large-scale structure of wind streams (the ion wind composition especially) in scales of hours and days allows one to determine the type and source of streams, whereas the MHD-parameters allow one to more accurately describe the small-scale structure (in minutes), especially in the cases of several streams interaction in the heliosphere. The detailed study of a small-scale structure of stream interaction regions provides the information required for developing MHD-models describing the processes of propagation and interaction of streams in the heliosphere and for predicting their geoefficiency.

At the present time, there is no generally accepted classification of the solar wind flows. There are various approaches to this problem depending on the goal of the study. In our paper, we propose the binary classification of the solar wind types by the main hydrodynamic parameters (velocity, temperature, and density) based on the statistical analysis of the solar wind. The analysis of the OMNIWeb one-minute data is performed for the period from 1996 to 2017, which encompasses solar cycle 23 and current solar cycle 24. Eight types of the solar wind are distinguished: fast-hot-dense, fast-hot-rarefied, fast-cold-dense, fast-cold-rarefied, slow-hot-dense, slow-hot-rarefied, slow-cold-dense, slow-cold-rarefied. These types occur with different frequency and are the consequences of different manifestations of solar activity. Of particular interest are the solar wind flows, the parameters of which deviate from the averages most significantly.

A binary classification of solar wind types is given according to three main hydrodynamic parameters—the proton speed, the proton temperature, and the proton density. Boundaries between the fast–hot–dense, fast–hot–rarefied, fast–cold–dense, fast–cold–rarefied, slow–hot–dense, slow–hot–rarefied, slow–cold–dense, and slow–cold–rarefied solar wind types are specified in the space of these variables. These types arise at different frequencies and originate from different sorts of solar activity. An analysis of 1-minute data from the OMNIWeb database is performed over the period from January 1, 2016, to September 30, 2017. In some cases, this classification scheme, which is quite simple and clear, allows one to identify the sources of the solar wind (coronal holes and coronal mass ejections), as well as to reveal long-term trends. The proposed scheme is compared with the methods used earlier in the literature to classify solar wind types.

Based on numerical and analytical approaches, a comprehensive physical and mathematical model determining the motion and destruction of natural cosmic bodies in the Earth atmosphere is created. Multilevel interrelated problems are considered, including simulation of the aeroballistics of meteoroids and their fragments taking into account their thermal and mechanical destruction; computation of airflow around a set of bodies (the meteorite fragments); and analysis of the problem of multiple “explosions” in atmosphere, which is inherent in meteoroids moving in the atmosphere after their fragmentation. The aim of the study is to resolve an important aspect of the asteroid and comet threat—the interaction of meteoroids with the atmosphere.

In the context of studying the problem of simulation of magnetic fields on the Sun, the structure of the field in the vicinity of two circular current loops with different mutual arrangement in space is considered. When the symmetry in the arrangement is sufficient, a system of magnetic surfaces created by the closed field lines arises. With a reduction in symmetry, isolated closed lines may exist. For the case of two identical current loops coupled perpendicularly, it is shown that the subsystems of these lines may be ordered in space in a complex manner. At large distances, a system of loops is equivalent to a dipole with a high degree of accuracy, while an approximate winding of the lines on the deformed toroids, encircling each of the loops, occurs at small distances. At intermediate distances, there are regions of both ordered and chaotic behavior of field lines. Results were obtained with the use of the numerical simulation method.

The paper presents the methods describing the behavior of lines of a three-dimensional vector field near null points of order greater than one assuming that the potential of that field satisfies the Laplace equation. Some general analytic solutions are presented for the second order case.

Separation of two meteoroid bodies is studied using modelling method based on a system of grids and solving adjoint aerodynamic and ballistic problems. Bodies of the same mass but different shapes were considered. Calculations were done for different combinations of the cylindrical bodies with their cross sections having a shape of square, elongated rectangular and circle. Initially the bodies were placed near each other on the line perpendicular to the flight direction. The lowest value of separation velocity was obtained for the bodies with circular cross section; the separation velocity is significantly increased for the bodies with elongated rectangular cross section due to rotation. Stable aerodynamic position of the bodies with elongated cross sections occurs when the bodies fly with a large side perpendicular to the flight direction. The lateral velocity acquired by each body appears to be primary determined by its own geometry and show no dependency on the shape of a neighboring body.

General principles of describing secondand higher-order null points of a potential magnetic field are formulated. The potential near a second-order null of the general form can be specified by a linear combination of four basic functions, the list of which is presented. Near secondand higher-order null points, field line equations often cannot be integrated analytically; however, in some cases, it is possible to present a qualitative description of the geometry of null vicinities with consideration of the behavior of field lines near rays outgoing from null, at which the field is radial or equals zero.

Storage of key reagents for amplification in a microfluidic device is decisive for point-of-care diagnostics. A simple approach of drying the reagents without special stabilizers by dehydration in a glass microchip is described. For loop mediated isothermal amplification of nucleic acids, a microchip device with two reactors was approbated. It was shown that the microchip device is suitable for detecting nucleic acids template of the Sacbrood virus. The experimental results obtained in microchip reactors with dry-stored primers were comparable to the results with non-dried primers. The shelf life of dehydrated primers without declined its reactivity turned out less than three months.