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In order to develop a methodological apparatus for assessing various stages of the life cycle of hybrid/electric propulsion units, the existing approaches to estimating the costs of developing, manufacturing and operating aircraft engines of the traditional propulsion units scheme for determining the cost framework and their further harmonization with the technical and economic boundary conditions of new elements in the hybrid/electric SU scheme are considered. The relevance of solving the problems of assessing the technical and economic efficiency and forecasting the cost of hybrid propulsion units is determined. To solve the tasks, a methodological approach to determining boundary conditions and criteria is proposed. Within the framework of this methodological approach, a preliminary assessment of the cost of the main stages of the life cycle of aircraft engines for various variants of traditional propulsion units was made. Based on the estimates obtained, criteria for the economic efficiency of using a hybrid propulsion unit of various capacities for civil aircraft were formed. A computational and parametric analysis of the cost estimation of variants of aircraft engines included in the propulsion unit of the traditional scheme is presented. The role of accounting and management accounting data in economic and mathematical models is determined, which makes it possible to qualitatively reflect the economic efficiency of the life cycle of aviation products.

The structural-phase state of the Al-Co-Cr-Cu-Fe-Ni system high-entropy alloy obtained by laser alloying of technically pure aluminium surface layers was investigated by XRD, EDX and metallographic analyses. It is shown that in the process of laser alloying the formation of an an ordered multicomponent substitution solid solution based on BCC lattice took place, which is typical for high-entropy alloys. The process of heterogeneous crystallization of high-entropy alloys AlCoCrCuFeNi and Al3CoCrCuFeNi was modeled taking into account cooling rates of the melt. It is established that the formation of the obtained structure is a consequence of high cooling rates of the melt and high content of aluminum in the laser alloying zone. The microhardness of the alloyed surface was higher compared to high-entropy alloys of this system obtained under equilibrium conditions and was equal to 6.59 GPa. Additional reasons that may affect the high values of microhardness are analysed.

The structure evolution of amorphous metallic alloys during different kinds of thermal effects is an important problem of disordered systems physics. A precise evolutional model would allow predicting the formation of such a structural state, providing the necessary physical and mechanical alloy properties.The paper is devoted to the problem of modelling the explosive crystallisation process in metal glasses induced by laser, supplemented by experimental results.A theoretical model of laser-induced explosive crystallisation in metal glasses is proposed. A pulse laser heating method for the surface processing was developed, making it possible to obtain two-layer structures with an adjustable thickness of the amorphous crystalline layer.The proposed model is assumed to test and optimes for metal glasses of other chemical compositions.A theoretical model of laser-induced explosive crystallisation in metal glasses allows for predicting and controlling structure changes to obtain the desired properties.The investigation of structure changes at rapid heating of amorphous alloys by experimental methods is very limited in obtaining data and their interpretation. For that reason, combining the modelling with experimental measurements is proposed. The results of this work have value for a scientist in material science, physics and engineering, which use nonequilibrium physical processes to obtain new materials, including nanoscale systems.

The article proposes a new approach to the implementation of a neuromorphic system based on a hybrid model of a neuron, made in a neuro-fuzzy basis. The closest analogue, the Neo-fuzzy neuron model, is described. A neurological cluster model, previously developed with the participation of the authors, was chosen as a prototype for constructing a hybrid model. The basic procedures for processing and teaching this model to map a given function, as well as additional procedures for coding pulse inputs and synthesis of pulse outputs are presented. Using these procedures, a new hybrid model of a spike neuron has been implemented, which reflects the function of the traditional model of Izhikevich's neuron. It is shown that the hybrid model requires less computing resources. On the basis of the new version of the hybrid model, a spike neuromorphic network was developed and tested to control the movements of a mobile robot along a given trajectory. It is assumed that, using a hybrid version of the neuron model, it is easier to implement a hardware version of spike neuromorphic networks than using neuron models based on differential equations. On the basis of such hardware-implemented networks, it is possible to create effective neuromorphic control systems for mobile robots. Key words Neuromorphic system, spike neuromorphic network, hybrid neuron model, neuron-fuzzy basis, mobile robot control. Acknowledgements This work was done as the part of the state task of the Ministry of Education and Science of Russia No. 075-00913-21-01 «Development and study of new architectures of reconfigurable growing neural networks, methods and algorithms for their learning».

This article proposes a solution for structural materials such as concrete and cement mortars dynamic properties investigation using experimental modal analysis technique. The studied dynamic characteristics of structural materials include the dynamic modulus of elasticity and the loss factor or its derivatives: the logarithmic oscillation decrement or the relative damping coefficient. Closed expressions are presented for determining the loss factor of mechanical vibrations, obtained on the basis of solving the differential equation for vibrations of a single-mass dynamic system. A method for calculating the loss factor based on the analysis of the spectrum of the transfer function of an oscillatory system loaded with an impulsive dynamic force is presented, in which the results of measuring accelerations at various points of the sample are used as a response. The experiments were carried out on short and long samples made from samples of structural materials - cement mortars with a density of 1500 - 1900 kg/m3 with special aggregates. Based on the solution of the equation of oscillations of a beam with distributed masses, a formula is presented for determining the dynamic modulus of elasticity of the beam material.

Significant changes in cellular and humoral immunity are observed in new coronavirus infection (COVID-19). The cytokine storm develops in cases of severe clinical course, being accompanied by significantly increased levels of pro-inflammatory cytokines, often associated with suppression of immune response. At the same time, the prediction of the immune status is an urgent task, thus allowing timely correction of current therapy. The aim of our research was to evaluate predictive capability for the immune system changes on the 6th day of COVID-19 disease when using standard therapy, or with addition of immunocorrector thymalin to the treatment regimen. A retrospective study was conducted in 87 patients with severe COVID-19. All patients were divided into 2 groups, i.e., (1) controls who received basic treatment; (2) basic treatment supplied with thymalin (10 mg, intramuscular injections daily for 5 days). Assessment of severity and clinical course of COVID-19, and basic treatment regimen for the patients corresponded to current version of the interim Guidelines from the Ministry of Health of the Russian Federation Prevention, diagnosis and treatment of a new coronavirus infection COVID-19. Laboratory studies included complete blood counts, immunogram parameters with the calculation of the ratio of certain types of leukocytes were performed on the 1st and 6th days of observation. Statistical evaluation was made using scripts of the specialized statistical analysis language R (http://cran.r-project.org) version 4.1.3. The blood parameters were evaluated using the binary classification method. The changes in parameters of cellular immunity were classified by means of ROC-analysis. We have found that the basic therapy of severely ill COVID-19 patients was not followed by recovery of immune status on the 6th day from the start of treatment. At marginal level, one can only suggest a probable prediction of increase in WBC and MON counts, a decrease in CD4+, NK and CD8+perNK, as well as the CD4+/CD8+ ratio. Addition of thymalin to the basic therapy is largely accompanied by the normalization of immunogram parameters. At the same time, it is possible to predict, with excellent rating, an increased number of T-LIM, including CD4+ and B-LIM, and, with good rating, an increase in the total numbers of LIM, as well as CD8+, HLA-CD3+DR+ and NK cells. The data obtained in severe cases of COVID-19 make it possible to predict changes in immune status, and, hence, the course of the disease, at a high degree of probability.

Low-temperature E×B plasmas are used in various applications, such as Hall thrusters for satellite propulsion, ion sources and magnetron discharges for plasma processing, and negative ion sources for neutral beam injection in fusion. The plasmas in these devices are partially magnetized, meaning that the electrons are strongly magnetized while the ions are not. They are subject to various micro- and macro-instabilities that differ significantly from instabilities in fusion plasmas. These instabilities are often triggered by the large difference in electron and ion drift velocities in the E×B direction. The possibility of maintaining a large electric field in the quasineutral plasma of Hall thrusters despite anomalous electron transport, or the presence of strong double layers associated with the azimuthal rotation of plasma structures (“rotating spokes”) in magnetron discharges and Hall thrusters are examples of the very challenging and exciting physics of E×B devices. The turbulence and instabilities present in E×B plasma devices constitute a major obstacle to the quantitative description of these devices and to the development of predictive codes and are the subject of intense research efforts. In this tutorial, we discuss the key aspects of the physics of low-temperature partially magnetized E×B plasmas, as well as recent advances made through simulations, theory, and experiments in our understanding of the various types of instabilities (such as gradient-drift/Simon-Hoh and lower hybrid instabilities, rotating ionization waves, electron cyclotron drift instability, modified two-stream instability, etc.) that occur in these plasmas.

In the context of the implementation of numerous innovative projects around the world, one of the urgent tasks of the modern theory of management accounting is the harmonisation of business processes within systems of various specialization (management, accounting, design and production) that form the organisational structure of the company and are at its various levels. The problem is the inconsistency of the activities of economic and design departments in the process of forming the concept of an innovative product, due to the lack of a model of the mechanism of their interaction at various stages of an innovative project. The article describes the initial stage of testing the hypothesis of the existence of an optimal model of management accounting and cost design systems (design department) interaction model at various stages of an innovation project. Within the framework of the study, a number of tasks were solved, in particular: the task of choosing the most effective research method from the list of methods used by the authors of similar scientific papers; the task of describing the mechanism of interaction of the considered intra-organisational systems in the context of the implementation of an innovative project; the task of establishing the identity of problematic issues arising from the interaction of the management accounting system and the design service at various enterprises. The purpose of the study is to test the hypothesis of the existence of an optimal model of management accounting and cost design systems interaction. Within the framework of the study with the participation of a representative group of three enterprises, the results characterising the current state of the management accounting and cost design systems were obtained. In practice, the enterprises under consideration face problems related to the management accounting and cost design systems interaction model, which are often accompanied by a low level of development of business processes and project management. As a result of the conducted research, indirect confirmation of the proposed hypothesis of the study was obtained.

The article is devoted to the research of the values of modern society in general, and Russian society in particular. It is shown that the culture of modern society is deprived of a system-forming center. In a culture of this type, human values are not taken into account. The value of freedom degenerates into individualization, and the value of equality into a normative value, into identification. In the situation of spreading the same values to different cultures, the problem of preserving the uniqueness of Russian society and culture arises. It is noted that the Russian society itself should be a value. For that, it is necessary that the values emanating from the state be in harmony with the values of society. Using the example of external signs of value features in such spheres of modern society as the state, economy, education, science, it is shown that the specificity of modern society, consisting in its "fluidity" and orientation to practice, does not allow members of our society to accept the high ideals declared by the state.

An important parameter of the compaction process of asphalt concrete mix by a vibrating roller is the resulting force exerted by the shaft on the compacted material. The magnitude and direction of this force determine the rolling efficiency and depend on the design parameters of the roller and the physical and mechanical characteristics of the compacted material. To establish these dependencies, a theoretical study of the stress-strain state of the asphalt concrete mixture in the contact zone with the vibrating roller was carried out using rheological modeling tools. Based on the obtained analytical dependences of the resulting force and the angle of deviation of the vector of the resulting force, a simulation model of the oscillatory system “roller – asphalt concrete mixture” was developed. Based on the simulation results, recommendations are given for adjusting the angle of deviation of the vector of the resultant force from the vertical. The use of these recommendations will increase the efficiency of compaction of asphalt concrete mix by reducing the number of passes of the roller, and, as a result, reducing the operating time.

The paper investigates the process of force interaction of a vibrating roller with a layer of asphalt concrete mixture. To describe the stress-strain state of the compacted layer during the interaction of the latter with a vibration roller, the Kelvin body was used. On the basis of the law of behavior of the Kelvin body, a simulation model has been developed, the result of which is a phase trajectory in the coordinates “force–displacement” for the system “drum–asphalt concrete mixture”. An analytical study of the characteristic points of the phase trajectory was carried out, as a result of which the relationship between the properties of the asphalt concrete mixture and the force effect in the area of contact of the roller with the compacted layer was established. In addition, a condition was obtained for continuous rolling of the asphalt-concrete layer with a vibrating roller, the observance of which makes it possible to increase the resource of the roller by reducing the wear of the latter. The results obtined can be used to establish the relationship between the operating modes of the vibratory roller and the properties of the compacted layer of the asphalt concrete mixture.

Operator splitting is a popular divide-and-conquer strategy for solving differential equations. Typically, the right-hand side of the differential equation is split into a number of parts that can then be integrated separately. Many methods are known that split the right-hand side into two parts. This approach is limiting, however, and there are situations when 3-splitting is more natural and ultimately more advantageous. The second-order Strang operator-splitting method readily generalizes to a right-hand side splitting into any number of operators. It is arguably the most popular method for 3-splitting because of its efficiency, ease of implementation, and intuitive nature. Other 3-splitting methods exist, but they are less well-known, and evaluations of their performance in practice are scarce. We demonstrate the effectiveness of some alternative 3-split, second-order methods to Strang splitting on two problems: the reaction-diffusion Brusselator, which can be split into three parts that each have closed-form solutions, and the kinetic Vlasov--Poisson equations that is used in semi-Lagrangian plasma simulations. We find alternative second-order 3-operator-splitting methods that realize efficiency gains of 10\%--20\% over traditional Strang splitting.

Peptide drug Thymalin, isolated from the calve thymus, is successfully used for the treatment of various immunopathologies, including those in older age groups. The molecular mechanism of the Thymalin immunoprotective action is due to the effects of the short peptides KE, EW, EDP in its composition. These short peptides can specifically bind to double-stranded DNA and/or histone proteins and regulate gene expression, synthesis of immune system proteins, activity of gerontogenes, and stimulate stem cell differentiation. Regulation of immunogenesis is a key factor preventing the development of the “cytokine storm” that develops in severe COVID-19. The purpose of this work is to study the effectiveness of Thymalin in severe COVID-19 in older patients. Patients administered with Thymalin against the background of a standard therapy (n = 36) manifested a more rapid clinical improvement, higher proportions of recovery from lymphopenia, faster normalization of the concentration of C-reactive protein, D-dimer, the number of lymphocytes and NK-cells in the blood, compared to patients who received a standard therapy only (n = 44). Thymalin halved hospital mortality in older patients with severe COVID-19. The results obtained showed the effectiveness of Thymalin administration in the complex therapy of patients with severe COVID-19.

We report here a simple hydrothermal synthesis of 100-200 nm flakes of tochilinite m(Fe1 xS)n(Mg,Fe)(OH)2 constructed by interchanging atomic sheets of iron sulfide and magnesium hydroxide as a representative of a new platform of multifunctional two-dimensional materials. The formation and characteristics of the material was studied using X-ray and electron diffraction, TEM, EDS, X-ray photoelectron and 57Fe Mössbauer and UV-vis-NIR spectroscopies, measurements of magnetization, dielectric permittivity, and zeta potential of aqueous dispersions. The reliable formation of tochilinite was ensured by a large excess of sodium sulfide, which induced negative zeta potential (about -30 mV) of tochilinite dispersions, whereas the potential approached zero for nearly-stoichiometric S/Fe precursor ratios. The assembly of the metal sulfide and hydroxide sheets driven by their opposite electric charges starts immediately after mixing the reagents at room temperature. The hydroxide layers contain Fe3+, not Fe2+, cations, the quantity of which was reduced and increased in the range 10 to 40% of Mg2+ by addition of Al and Li, respectively. The Fe-deficient sulfide sheets contain comparable amounts of high-spin Fe3+ and Fe2+ centers, and minor S-S bonding. The room-temperature Mössbauer spectra were fitted with several doublets with the chemical shift of 0.35-0.4 mm/s and varying quadrupole splitting. Magnetic ordering at 4.2 K manifested by three six-line patterns with the hyperfine fields of ~290, 350 and 480 kOe attributed to overlapped Fe2+-S and Fe3+-OH signals, Fe3+-S centers and some Fe3+-O centers, respectively; a paramagnetic behavior was observed in SQUID experiments. The temperature and frequency dependences of permittivity revealed the activation energy of ~0.3 eV, probably, due to electron transitions involving Fe 3d states. A series of UV-vis absorption maxima were explained in terms of the high-index all-dielectric Mie resonance and the ligand-to-metal charge transfer alike Fe-S clusters in proteins. Prospective properties and applications of the materials are discussed.

Introduction. The adaptive overload of the central nervous system, caused by occupational stress, leads to the disruption of complex operational activities in the ambulance station workers and an increasing number of errors in medical decision-making towards the end of the work shift.Aim. To assess the level and prevalence of changes in the work of the central nervous system (CNS) under the influence of occupational stress.Materials and methods. The study involved 35 workers (medical and nursing staff) of ambulance station (19 men and 16 women aged 20 to 55 years). Electroencephalogram (EEG) was recorded at rest for 3 minutes, according to international scheme 10-20 in six leads: F3, F4, T3, T4, P3, P4. The following rhythmic activity indicators were used: THETA rhythm (4–8 Hz), ALPHA rhythm (8–12 Hz), BETA rhythm (BETA, 12–25 Hz) and their ratios.Results and discussion. When analyzing the overall activity, there is a decrease in all the studied parameters. At the same time, THETA, BETA and the total power of all ranges showed significant dynamics. In spatial analysis, the most noticeable decrease in activity in the frontal lobes (F3, F4) is responsible for motor behavior (premotor area of the cortex), executive functions (behavior control, inductive reasoning, planning), short-term and spatial memory, attention (spatial and motor). The decrease in activity in the temporal (T3, T4) and parietal (P3, P4) departments is observed only in some indicators.Conclusions. Professional workload during the 24 hour shift has a predominant effect on the activity of the frontal lobes, reducing the ability to control and plan complex (precise) motor functions, visual-spatial attention and planning abilities. These mechanisms are key to the professional work of the personnel of the emergency medical service and determine the number of errors.

The final stage in the formation of the structure of the upper layer of the road surface is its compaction. Evaluation of compaction performance can be made by comparing the maximum drumside contact pressure with the tensile strength of the material to be compacted. As a result of considering the contact interaction of the roller with the layer of material, the relationship between the design parameters of the roller and the stress-strain state of the layer of the compacted material has been established. A method for evaluating the effectiveness of the use of a road roller is developed on the basis of measuring the arc length of the contact of its roller with the compacted material. For the practical implementation of the proposed methodology, a description of a device is given that allows monitoring the efficiency of the process of compaction of bitumen-mineral materials by a road roller.

Modern businesses throughout the world operate in a market characterized by constant changes. These changes are becoming more dynamic from year to year. It is the project-based approach that will allow one to solve problems and ensure high efficiency of project-oriented operations. The purpose of the study is a comparative analysis of the impact of the use of IT project management methodologies of Kanban and Scrum on a company's financial performance. The authors identify the essence of the agile methodology, its conceptual foundations, and explore the key aspects of its efficient implementation. The popularity of the practical application of the agile approach in various business areas is analyzed. The authors also choose the best methodology for a particular IT project for the optimization of such economic and financial indicators as project cost, profit from project implementation, and implementation time. The key differences between the most popular agile technologies are identified. The requirements for forming an agile team are examined considering the main issues during the implementation of agile management technologies. The primary stages in the implementation of an IT project using the Scrum methodologies are defined.

The aim of the work was a comparative study of Tocilizumab and Thymalin effects on the morphological composition and indicators of the blood clotting system in COVID-19 of middle aged and elderly patients. Severe COVID-19 patients were divided into 3 groups: 1st - control (basic therapy), 2nd - basic therapy +Tocilizumab, 3rd - basic therapy +Thymalin. Hospital mortality in COVID-19 patients after standard therapy, Tocilizumab and Thymalin application was 40,9; 28,4 and 20,6% accordingly. The number of platelets increased by 1,5 times, the concentration of fibrinogen in blood decreased by 78% and activated partial thromboplastin time decreased by 9,3% in patients taking Tocilizumab. Under the influence of Tocilizumab, the platelet/white blood cell and platelet/lymphocyte ratios increased by 1,6 and 1,4 times, which may be a predictor of an unfavorable outcome of COVID-19. Thymalin increased the number of lymphocytes and monocytes by 2 times, the number of leukocytes - by 1,3 times, the number of platelets in the blood - by 1,5 times. Thymain decreased the platelet/lymphocyte and neutrophil/lymphocyte ratios by 1,4 times and 2 times. The use of Thymalin decreased the level of fibrinogen, lactate dehydrogenase and D-dimer in the blood by 1,2; 1,8 and 1,7 times, respectively. Thymalin, compared with Tocilizumab, meets the principles of pathogenic therapy for severe COVID-19 of middle aged and elderly patients to a greater extent, having a normalizing effect on the morphological composition and indicators of the blood clotting system.Цель работы — сравнительное исследование действия Тоцилизумаба и Тималина на морфологический состав и показатели свертывающей системы крови при COVID-19 у лиц среднего и пожилого возраста. Пациенты с тяжелой формой COVID-19 были разделены на три группы: 1-я — контрольная (базисная терапия); 2-я — базисная терапия +Тоцилизумаб; 3-я — базисная терапия +Тималин. Госпитальная летальность у пациентов с COVID-19 после стандартной терапии, Тоцилизумаба и Тималина составила соответственно 40,9; 28,8 и 16,2%. У пациентов, принимавших Тоцилизумаб, в 1,5 раза повышалось число тромбоцитов, на 78% снижалась концентрация фибриногена в крови и на 9,3% уменьшалось активированное частичное тромбопластиновое время. Под действием Тоцилизумаба в 1,6 и 1,4 раза повышались соотношения тромбоциты/лейкоциты и тромбоциты/лимфоциты соответственно, что может быть предиктором неблагоприятного исхода COVID-19. Под действием Тималина у пациентов в 2 раза повышалось количество лимфоцитов и моноцитов, в 1,3 раза —лейкоцитов, в 1,5 раза —тромбоцитов. Соотношения тромбоциты/лимфоциты и нейтрофилы/лимфоциты снижались в 1,4 раза и 2 раза соответственно. Применение Тималина снижало концентрацию фибриногена, лактатдегидрогеназы и D-димера в крови соответственно в 1,2; 1,8 и 1,7 раза. Использование Тималина относительно тоцилизумаба при тяжелом течении COVID-19 у лиц среднего и пожилого возраста оказывает более выраженное модулирующее влияние на морфологический состав и показатели свертывающей системы крови.

Representatives of the genus

For centering the cooling jackets of CCM tube molds relative to the tube, bolts twisted into the jacket are used. The adjustment is made manually, as a result the annular gap between the sleeve and the jacket can have a significant deviation from the specified values. The gap function is to cool the structure by passing water. Taking into account that almost all the modern CCMs for casting long, bloom and round billets are equipped with tube molds, creating a mold design in which the gap between the tube and the cooling jacket is formed with a high degree of accuracy, ensuring uniform heat removal from the walls of the tube is an urgent task. This is necessary to ensure a uniform thickness of the shell of the solidifying billet. The conditions were considered for the formation of a uniform shell of a solidifying ingot in a mold and the production of a billet that meets the requirements for its surface and geometric dimensions, the absence of internal and external cracks of thermal origin. It was shown that the violation of the alignment of the cooling jacket and the tube surfaces results in violation of the uniformity of the cooling water flow. The difference in the volume of water flowing in various parts of the gap between the tube and the jacket can reach 40%. When casting billets with diameters of 600 and 550 mm, the difference in heat flows due to misalignment in existing molds can be 30–40% and 25–35% respectively, and with a cross section of 300×400 mm – 13–23%. In order to eliminate these shortcomings, a new design of the tube mold was developed in VNIIMETMASH (Moscow), in which the gap between the sleeve and the cooling jacket is formed with high accuracy, ensuring uniform heat removal from the walls of the tube and obtaining a uniform thickness of the shell of the solidifying ingot. This will ensure that the casted billet meets the requirements for its quality parameters and geometric dimensions. The diagram of the designed mold for the bloom CCM, which produces billets with a cross section of 340×380 mm is presented.

The article considers the problem of the correlation to the universality of the East Asian world with the global trends leveling the differences on the example of the political development of the East Asian countries and the processes of economic integration

The article deals with the determination of the reservoir properties of Permian-age carbonate rocks. There is a section dissection technique, taking into account the fossil organisms prevailing for a particular geological age. It was noted a high content of silica in the lower Artinskian deposits of Toravey and Varandey fields of the Komi Republic. The presence of silicon is associated with an increase in the population of siliceous sponges during this period of sedimentation; this fact caused the maximum values of porosity and permeability in the corresponding intervals. However, this was also the reason for the high values of the residual water saturation factor and, as a result, low oil flow rates from the lower Artinskian stage. The need for detailed correlation and accounting for the content of fossils in the rocks when dissecting the well section made it necessary to systematize the available actual material on core and well testing. It became obvious that the separation of reservoirs and stages at the qualitative level isn't possible, so quantitative estimates of the parameters that are significantly different for the upper and lower Artinskian deposits and allow you to dissect the well section were proposed.

Multichannel digital receivers based on the signal processing technology involving undersampling are used for the instantaneous wideband analysis of the electronic environment. One of the most common algorithms for measuring input signal’s carrier frequency in such receivers includes unfolding of the signal’s spectrums from the first Nyquist zone of all receiver’s channels to the single frequency axis and searching for the frequency where the spectrum components from all of the receiver’s channels coincided. Performance of the signal detector, which uses this algorithm in its operation, was not studied. In the absence of a mathematical description of such a detector, evaluating the digital undersampling receiver’s sensitivity becomes possible only in the late stages of prototyping when it can be done through experimental study. Additionally, it is impossible to set a detection threshold in the receiver according to the Neyman-Pearson criterion, which hardens building constant false alarm rate (CFAR) systems based on this type's receivers. This paper aims to develop the mathematical description of the digital undersampling receiver's detector and then, using this model, to get expressions and computer models to evaluate the characteristics of such receiver even in early stages of its development. This paper's main result is the developed mathematical tools necessary to evaluate the multichannel digital undersampling receiver’s signal detector performance. It is shown that the false alarm probability in such a detector does not exceed some value no matter how small the detection threshold is. The expression for evaluating the maximum false alarm probability by the receiver’s parameters is also presented in the paper alongside the true positive rate plots as a function of signal-to-noise ratio for the three-channel receiver. These results can be used in evaluating the digital undersampling receiver’s characteristics in the early stages of its development. It allows one to choose optimal values of the receiver’s parameters which are hard and expensive to change after prototyping is done, and there is an opportunity to evaluate the receiver’s characteristics experimentally. Moreover, the obtained mathematical expressions make it possible to set the receiver's detection threshold according to the Neyman-Pearson criterion and build on its base a CFAR-systems widely used for wideband signal analysis.

The metagenome of foulings from sulfidic spring "Serovodorodny" (Tatarstan, Russia), where members of the genus

Effects of finite ion temperature on the plasma flow in the converging–diverging magnetic field, the magnetic mirror, or equivalently, magnetic nozzle configuration are studied using a quasineutral paraxial two-fluid MHD model with isothermal electrons and warm magnetized ions. The ion acceleration was studied with an emphasis on the role of the singularity at the sonic point transition. It is shown that the regularity of the sonic point defines a global solution describing plasma acceleration from subsonic to supersonic velocity. Stationary accelerating solutions were obtained and compared with the time dependent dynamics, confirming that the solutions of the time-dependent equations converge to the stationary solutions and, therefore, are stable. The effects of the ion pressure anisotropy were analyzed using the Chew–Golberger–Low model and its generalization. It is shown that the mirror force (manifested by the perpendicular ion pressure) enhances plasma acceleration. The role of ionization and charge exchange on plasma flow acceleration have been investigated.

Introduction. Simultaneous operation of numerous sources of radio emission form complex signal environment. Different devices with the common name “wideband analyzers” (WBA) are widely used to analyze and to control such environment. There is currently a need for developing the quantitative characteristics of a complex signal environment, which will make it possible to predict the stability of the WBA operation. Aim. The development of the indicator of the signal environment complexity, which will make possible the quantitative assessment of such environment. Materials and methods. To provide the desired indicator, simulation and mathematical tools for random events description are used. All calculations are performed using MatLab. Results. The principles of disturbances in the WBA receiver and algorithmic errors in the processing of overlapped signals are described. To quantify the “complexity” of the signal environment it is proposed to use the probability that pulses from several sources overlap in time. This allows one to compare signal environments with each other. The new analytical expression for estimating the pulse overlap probability is proposed. Functions of the pulse overlap probability from the complex signal environment parameters were obtained. Conclusion. According to the comparative analysis of the calculations using proposed analytical expression and simulation, the new expression allows one to achieve the calculation speed up to 6 orders of magnitude higher with an error below 7% compared to the simulation. The high performance of the calculations using the proposed expression allows one to simulate the complex signal environment in dynamics more efficiently.