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We set up the problem of ponderomotive separation and acceleration of ions with different charge-to-mass ratios under the influence of Alfvén waves, which constantly exist in the magnetosphere in the form of geomagnetic pulsations. Formulas for partial ponderomotive forces acting on light and heavy (metallic) ions are derived. In the quasi-hydrodynamic approximation, a system of equations is obtained which describes the distribution of ions along magnetic field lines in Earth’s magnetosphere. The Clarke number, which characterizes plasma metallicity, is found to be maximum at a minimum magnetic field on the field line along which the Alfvén wave propagates. This leads to the accumulation of heavy ions at the top of the field line at the point of its intersection with the magnetic equator. The theoretical conclusions agree with satellite measurements of the distribution of heavy ions along field lines in Earth’s magnetosphere.

This methodical paper explores the possibility of estimating the peak electron density of the F2-region of the ionosphere (NmF2) under different conditions, using data on the frequency of spectral bands (harmonics) of the ionospheric Alfvén resonator (IAR) oscillation. We describe a simple technique for tracking the frequency of spectral bands during the day by measuring their position on the plot of the IAR daily dynamic spectrum. Through calculations within the framework of the global ionospheric model IRI-2016, we verify the correctness of the comparison of the frequencies of resonant bands, measured at one point, with data from radio sounding, performed at other points remote from IAR frequency measurement sites at a distance. We propose an algorithm for comparing NmF2, measured by a radiosonde, with frequencies of spectral lines by precalculating the evaluation factor. It is formed on the basis of a nonlinear combination of the frequencies of the three observed harmonics. Then the time series of this factor is compared with the results of radio sounding, and correlation and regression coefficients, as well as estimation errors are calculated. Using the material on rare cases of round-the-clock observation of IAR oscillations in the winter months of 2011–2012, we trace the dependence of the average error in determining the peak electron density on local time. We present the data on the most favorable local time intervals for determining NmF2 from IAR harmonic frequencies depending on season. Some additional factors are discussed which affect the accuracy of estimates and determine the frequency range of IAR oscillations.

Method for calculating statically indeterminate frames taking into account plastic deformations, which is based on the use of a schematized diagram of material with hardening is proposed. Two types of standard beams with supports are used during the implementation of the displacement method (DM) like the elastic solution of the problem: “fixed” - “pinned” and “fixed” – “fixed”, but unlike the elastic solution, standard beams contain special zones that besides elastic part include elasto-plastic zone (EPZ), plastic zone (PZ) and reinforcement zone (RZ). Therefore, as the stresses in these zones did not exceed the yield stress in the nonlinear frame calculation, we took measures to transform the PZs into equal strength plastic zones (ESPZ). The calculations were made for both types of beams for all unit and load impacts. The frame calculation consists of three stages (elastic, elasto-plastic and plastic). At the elastic and elasto-plastic stages, yield moment and plastic moment diagrams and the corresponding loads are determined. For a practical use of the DM in a nonlinear frame calculation, two simplifying prerequisites are introduced, with the help of which a stress-strain state is modeled in two zones: EPZ and PZ. According to the prerequisites, deformation of fibers occurs without hardening in EPZ and with hardening in PZ. The plastic stage of the calculation is performed at a given length of the PZ using the method of sequential loadings. At each iteration with small loading steps, incremental equations for DM are written, which establish relations between incremental moments and the incremental load, which allows us to build a resulting moment diagram. This diagram represents a sum of the moment diagram obtained at the elastic and elasto-plastic stages and the diagrams of incremental moments at all previous loading steps of plastic stage. According to the resulting diagram, the length of the PZ can be calculated, together with the limiting load. The calculation is considered complete if the length of the PZ does not exceed the specified value within the margin of error. Proposed algorithm is illustrated with an example of static calculation of 2-storey steel frame which perceives horizontal load actions that model a seismic impact.

We have studied the properties of impulsive geomagnetic disturbances, which are observed synchronously at the network of induction magnetometers of the Institute of Solar-Terrestrial Physics (ISTP SB RAS) and Canadian stations of the CARISMA project [Mann, et al., 2008]. A feature of the pulses we detected is that their frequency range (f~5–30 Hz) lies at the junction of the ranges of two known classes of electromagnetic oscillations: ultra-low-frequency (ULF) oscillations (f

See the retraction notice BIO Web of Conferences 138, 00001 (2024), https://doi.org/10.1051/bioconf/202413800001

See the retraction notice BIO Web of Conferences 138, 00001 (2024), https://doi.org/10.1051/bioconf/202413800001

To effectively manage the traffic flow in order to reduce traffic congestion, it is necessary to know the volumes and quantitative indicators of this flow. Various detection methods are known for detecting a vehicle in a lane, which, in turn, have their own advantages and disadvantages. To detect vehicles and analyse traffic intensity, the authors use a pulse coherent radar (PCR) sensor module. Testing of various modes of operation of the radar sensor was carried out to select the optimal mode for detecting vehicles. The paper describes a method for fixing vehicles of different sizes, filtering and separating the vehicle from the traffic flow. The developed vehicle detection device works in conjunction with signal traffic lights, through which traffic control takes place. The signal traffic lights, which have their own sensors and control units, communicate with each other via a radio channel; there is no need for cable laying. The system is designed to work on road maintenance sites. The paper describes the experimental data when testing on a separate section of the road. The experiment showed the advantage of traffic lights (cars passed the regulated traffic light faster) from the point of view of calculating the traffic flow over the normal traffic light operation. Reducing downtime in traffic jams, in turn, has a beneficial effect on the environmental situation, since at the moment internal combustion engines prevail in vehicles.

FDM is used for printing parts from thermoplastic polymers, polymer matrix composites, biocomposites or polymer-ceramic composites, nanocomposites and fiber-reinforced composites. The main disadvantage of this method is the reduced physical and mechanical characteristics due to the presence of pores and poor adhesion of layers. The post-treatment is one of the ways to improve this properties. The heat treatment has the greatest impact among all types of post-treatment processing on the surface quality and physical and mechanical properties of finished products. The paper studies the physical and mechanical properties of samples from ABS plastic (REC brand) printed by FDM and subjected to thermal post-treatment. Two methods of thermal post-treatment were considered: in NaCl powder and in closed form with pressure. The test results of the printed samples were compared with the test results of the samples obtained by injection molding. Comparison of strength and porosity showed that the properties of printed samples after post-treatment by both methods are comparable to the properties of samples obtained by injection molding.

This article provides an in-depth look at implementing parallel SQL query processing using the Microsoft SQL Server database management system. It examines how parallelism can significantly accelerate query execution by leveraging multi-core processors and clustered environments. The article explores SQL Server's sophisticated parallel processing capabilities including automatic query parallelization, intra-query parallelism techniques like parallel joins and parallel data aggregation, as well as inter-query parallelism for concurrent query execution. It covers key considerations around effective parallelization such as managing concurrency and locks, handling data skew, resource governance, and monitoring. Challenges like debugging parallel plans and potential bottlenecks from excessive parallelism are also discussed along with mitigation strategies. Real-world examples demonstrate how judicious application of parallel processing helps optimize complex analytics workloads involving massive datasets. The insights presented provide guidance to database developers and administrators looking to enable parallel SQL query execution in SQL Server environments for substantial performance gains and scalability.

The article is dedicated to the anniversary of the discovery of Alfvén waves. The concept of Alfvén waves has played an outstanding role in the formation and development of cosmic electrodynamics. A distinctive feature of Alfvén waves is that at each point in space the group velocity vector and the external magnetic field vector are collinear to each other. As a result, Alfvén waves can carry momentum, energy, and information over long distances. We briefly describe two Alfvén resonators, one of which is formed in the ionosphere, and the second presumably exists in Earth’s radiation belt. The existence of the ionospheric resonator is justified theoretically and confirmed by numerous observations. The second resonator is located between reflection points located high above Earth symmetrically with respect to the plane of the geomagnetic equator.

The Pc1 ultralow-frequency electromagnetic waves (frequency range 0.2–5 Hz), also known as pearl necklace, are a unique phenomenon in near-Earth space physics. Many properties of pearls remain a mystery, despite the research of prominent cosmophysicists for more than half a century. In the proposed review, we briefly outline the main points of the so-called standard model, which is widely used to interpret Pc1. Next, we focus on the criticism of the standard model and on the identification of open problems in the Pc1 theory. The general conclusion is that it is necessary to develop new ideas outside the framework of the standard model in order to understand the processes of excitation and propagation of Pc1 waves in Earth’s magnetosphere.

In the paper, we present the result of an experimental study of north-south asymmetry of ultralow-frequency electromagnetic oscillations IPCL. This study is based on observations made at Mirny Observatory (Antarctica). IPCLs are excited in the dayside sector of the auroral oval in the range 3–10 min periods and represent one of the most powerful types of oscillations of Earth's magnetosphere. These oscillations were discovered in the 1970s during IPhE AS USSR polar expeditions organized by Prof. V.A. Troitskaya. We have shown that IPCL activity in Mirny depends on the inclination (north-south asymmetry) of interplanetary magnetic field (IMF) lines to the plane of the geomagnetic equator before the front of the magnetosphere. The result suggests a controlling exposure of IMF on the magnetospheric oscillations and gives rise to the hypothesis that IPCL are forced oscillations of a nonlinear dynamical system whose major structural elements are dayside polar cusps. The paper is dedicated to the memory of Professor V.A. Troitskaya (1917–2010).

It has been one hundred years since the birth of the outstanding scientist Professor V.A. Troitskaya. Her remarkable achievements in solar-terrestrial physics are widely known. For many years, Valeria A. Troitskaya was the President of the International Association of Geomagnetism and Aeronomy. This article deals with only one aspect of the multifaceted creative activity of V.A. Troitskaya. It relates to the problem of sources of ultra-low frequency (ULF) electromagnetic oscillations and waves outside Earth’s magnetosphere. We were fortunate to work under the leadership of V.A. Troitskaya on this problem. In this paper, we briefly describe the history from the emergence of the idea of the extramagnetospheric origin of dayside permanent ULF oscillations in the late 1960s to the modern quest made by ground and satellite means for ULF waves excited by solar surface oscillations propagating in the interplanetary medium and reaching Earth.

The paper reviews studies of the dynamics of relativistic electrons in the geosynchronous region. It lists the physical processes that lead to the acceleration of electrons filling the outer radiation belt. As one of the space weather factors, high-energy electron fluxes pose a serious threat to the operation of satellite equipment in one of the most populated orbital regions. Necessity is emphasized for efforts to develop methods for forecasting the situation in this part of the magnetosphere, possible predictors are listed, and their classification is given. An example of a predictive model for forecasting relativistic electron flux with a 1–2-day lead time is proposed. Some questions of practical organization of prediction are discussed; the main objectives of short-term, medium-term, and long-term forecasts are listed.

We study frequency modulation of serpentine emission (SE), using data from the Vostok Antarctic station. It is shown that the previously observed 5-minute modulation of the SE carrier frequency is the most prominent and stable in the emission spectrum. Frequency fluctuations of this period are present in about 70 % of the total SE observation time under moderately quiet geomagnetic conditions (Kp=0–2). We performed a per-pixel processing of SE dynamic spectra and found that the power spectrum of the signal frequency modulation contains a clearly vis-ible peak at periods close to 5 minutes. A detailed study shows the emission spectrum matching the frequency range of the solar photospheric oscillations. The results of the analysis allow us to conclude that the 5-minute modulation of the SE carrier frequency can be viewed as a reflection of photospheric fluctuations with the same period that is typical for the solar eigenoscillations.