252 research outputs found

    Study of the physical properties of crystalline rocks in the southeast Voronezh anteclise

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    The physical properties of rocks, in the crystalline mass of the Voronezh anteclise, were studied. The study of the physical properties of rocks is important for the improvement of geophysical methods for mapping crystalline rocks in the foundation and exploration of different geological objects which are associated with the crystalline foundation, covered by the sedimentary mantle. It is found that: (1) rocks in the crystalline foundation are very different in physical properties; (2) the physical properties are closely related to their substance composition and genesis; (3) petrographic properties give clues of rock afficiation to certain complexes; and (4) physical and magnetic properties should be examined by petrography, chemical and X-ray analysis

    Nonlinear slow magnetoacoustic waves in coronal plasma structures

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    Context. There is abundant observational evidence of longitudinal waves in the plasma structures of the solar corona. These essentially compressive waves are confidently interpreted as slow magnetoacoustic waves. The use of the slow waves in plasma diagnostics and estimating their possible contribution to plasma heating and acceleration require detailed theoretical modelling. Aims. We investigate the role of obliqueness and magnetic effects in the evolution of slow magnetoacoustic waves, also called tube waves, in field-aligned plasma structures. Special attention is paid to the wave damping caused by nonlinear steepening. Methods. We considered an untwisted straight axisymmetric field-aligned plasma cylinder and analysed the behaviour of the slow magnetoacoustic waves that are guided by this plasma structure. We adopted a thin flux tube approximation. We took into account dissipation caused by viscosity, resistivity and thermal conduction, and nonlinearity. Effects of stratification and dispersion caused by the finite radius of the flux tube were neglected. Results. We derive the Burgers-type evolutionary equation for tube waves in a uniform plasma cylinder. Compared with a plane acoustic wave, the formation of shock fronts in tube waves is found to occur at a larger distance from the source. In addition, tube waves experience stronger damping. These effects are most pronounced in plasmas with the parameter β at about or greater than unity. In a low-β plasma, the evolution of tube waves can satisfactorily be described with the Burgers equation for plane acoustic waves

    Cut-off period for slow magnetoacoustic waves in coronal plasma structures

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    Context. There is abundant observational evidence of longitudinal compressive waves in plasma structures of the solar corona, which are confidently interpreted in terms of slow magnetoacoustic waves. The uses of coronal slow waves in plasma diagnostics, as well as analysis of their possible contribution to coronal heating and the solar wind acceleration, require detailed theoretical modelling. Aims. We investigate the effects of obliqueness, magnetic field, and non-uniformity of the medium on the evolution of long-wavelength slow magnetoacoustic waves guided by field-aligned plasma non-uniformities, also called tube waves. Special attention is paid to the cut-off effect due to the gravity stratification of the coronal plasma. Methods. We study the behaviour of linear tube waves in a vertical untwisted straight field-aligned isothermal plasma cylinder. We apply the thin flux tube approximation, taking into account effects of stratification caused by gravity. The dispersion due to the finite radius of the flux tube is neglected. We analyse the behaviour of the cut-off period for an exponentially divergent magnetic flux tube filled in with a stratified plasma. The results obtained are compared with the known cases of the constant Alfven speed and the pure acoustic wave. Results. We derive the wave equation for tube waves and reduce it to the form of the Klein–Gordon equation with varying coefficients, which explicitly contains the cut-off frequency. The cut-off period is found to vary with height, decreasing significantly in the low-beta plasma and in the plasma with the beta of the order of unity. The depressions in the cut-off period profiles can affect the propagation of longitudinal waves along coronal plasma structures towards the higher corona and can form coronal resonators

    Chromosome Abnormalities and Hematopoietic Stem Cell Transplantation in Acute Leukemias

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    The chapter considers specific treatment options, including allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), in patients with some prognostically proven cytogenetic variants as monosomal ones, complex and hyperdiploid karyotypes, like chromosomal translocations t(v;11)(v;q23), t(3;3)/inv(3); t(8;21), t(9;22), etc. Important prognostic role of additional chromosome abnormalities was shown for the patients with t(8;21) and t(9;22). Hence, it is evident that allo‐HSCT in patients with poor risk cytogenetic variant must be performed as early as possible, i.e., during first complete remission

    The influence of students’ intelligence types and personality traits on academic performance in distance learning in the digital environment

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    The academic paper investigates the influence of students’ intelligence types and personality traits on academic performance in order to increase the remote (distance) or online learning effectiveness. The research was conducted in 2019–2021 on the basis of three groups of bachelor students who studied in different training forms, namely: full-time (classroom) form in 2019 and 2021 and remote (distance) form in 2020. The students were tested annually in accordance with J. Bruner’s methodology adapted by G.V. Rezapkina in order to determine the leading intelligence types; as well as according to the Russian-language version of the Big Five Inventory questionnaire adapted by S.A. Shchebetenko for the purpose of analysing students’ personal traits. The data obtained in the full-time (classroom) and remote (distance) form of training were processed statistically and compared with each other for interpretation and the practical recommendations formation. The research result was an empirical model of the intelligence types and personality traits influencing academic performance in different training forms. Therefore, as a positive factor in the transfer to distance training mode, the authors highlighted the expressiveness of students’ creative thinking. Conversely, the prevalence of the verbal-logical intelligence type is rather a factor in favour of the classic classroom interaction format. Regardless of the chosen training form, the general relevance of the activation and adaptation of students of humanitarian specialties with a pronounced visual-figurative and subject-effective thinking is emphasised. Previously obtained data on the general positive influence of such personal qualities as: benevolence, conscientiousness and openness to new experience on the training effectiveness are also confirmed. Neuroticism, on the other hand, is an insignificant personal factor that has a negative impact in the framework of the classroom format, and the positive influence in distance training mode. By the way, a hypothesis has been put forward about the lower efficiency of online (as opposed to full-time) team activities, including design works in groups with pronounced extraversion

    ANALYSIS AND ASSESSMENT OF PERSONNEL CAPACITY OF THE ORGANIZATION’S STAFF AT PRESENT STAGE

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    The existing methods and approaches for analysing an organization’s personnel capacity have been considered, a retrospective review of the well-known classifications of Russian scientists has been carried out. The authors have studied the papers devoted to the practical aspects of assessing the personnel capacity of industrial enterprises in the context of a number of areas, including: personnel management, sustainable development management, increasing the competitiveness and market value of a company. A new approach to analysing personnel capacity has been proposed in the form of assessment of personnel security or the current level of personnel risks, which are, in turn, attributed to such components of personnel capacity as qualification / working experience, ability / speed of reproduction of labor resources

    Effect of local thermal equilibrium misbalance on long-wavelength slow magnetoacoustic waves

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    Evolution of slow magnetoacoustic waves guided by a cylindrical magnetic flux tube that represents a coronal loop or plume, is modeled accounting for the effects of finite gas pressure, weak nonlinearity, dissipation by thermal conduction and viscosity, and the misbalance between the cooling by optically thin radiation and unspecified heating of the plasma. An evolutionary equation of the Burgers–Malthus type is derived. It is shown that the cooling/heating misbalance, determined by the derivatives of the combined radiative cooling and heating function, with respect to the density, temperature, and magnetic field at the thermal equilibrium affect the wave rather strongly. This effect may either cause additional damping, or counteract it, or lead to the gradual amplification of the wave. In the latter case, the coronal plasma acts as an active medium for the slow magnetoacoustic waves. The effect of the cooling/heating misbalance could be important for coronal slow waves, and could be responsible for certain discrepancies between theoretical results and observations, in particular, the increased or decreased damping lengths and times, detection of the waves at certain heights only, and excitation of compressive oscillations. The results obtained open up a possibility for the diagnostics of the coronal heating function by slow magnetoacoustic waves

    The Concept of Development of Monitoring Systems and Management of Intelligent Technical Complexes

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    Conceptual approaches to improving the system of monitoring and managing the functional capabilities of intelligent technical complexes of buildings and transport and technological machines of mining enterprises are defined. Criteria are proposed for the efficiency of functioning of automatic systems for controlling the movement of transport-technological machines, taking into account the probabilistic nature of system-forming factors. The scheme of scientific and methodological research on the improvement of automation systems and traffic control in the automotive transport is presented. The perspective directions of the formation of control functions for the movement of vehicles based on the use of intelligent automated systems are substantiated. The stages of the life cycle of technical systems for monitoring the movement of vehicles, taking into account the features of their operation. A technique has been developed for the optimal use of technical means of control in the field of providing control and supervisory functions in the operation of vehicles, and the dependence of determining the financial costs of maintaining their efficiency has been determined
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