Functional integration of brain regions in children with speech disorders from the positions of sexual dimorphism and interhemispheric functional asymmetry

The aim of the study was to study the features of the functional integration of brain zones, taking into account the functional dominance of the hemispheres and sexual dimorphism in the process of prospective observation.В статье рассматриваются особенности функциональной интеграции зон мозга с учетом функциональной доминантности полушарий и полового диморфизма в процессе проспективного наблюдения

Mild neurological dysfunction as a marker of cognitive and behavioral disorders in children

В статье рассматриваются признаки легкой неврологической дисфункции и их связи с основными показателями психомоторного развития у детей низкого риска развития заболеваний в возрасте от 2 до 4 лет.The aim of this study is to detect minor neurological dysfunction (MND) signs and their association with the main parameters of neurodeve-lopment in low-risk children at the ages of 2.5-4 years

Local Temperature Distribution on the Spacecraft Surface under Uneven Solar Radiation

Solar radiation is the main factor to determine the thermal state of a spacecraft (SC) when it moves to the sunlit portion of the Earth orbit and moves away from the Earth. The extent of the solar radiation impact on the SC temperature state depends, primarily, on the interaction of this radiation with the surface portions of the SA body and the design elements that are placed outside the main body. To ensure the required SC temperature surfaces are used various coating and screen-vacuum thermal insulation, as well as multilayer optical solar reflectors with a thickness being in the range from tenths of a millimeter to 15 − 20 mm.When designing the SC, to predict their temperature state at various stages of operation are used mathematical models of various levels of complexity, including models related to the solution of inverse problems for determining the conditions of the thermal effects on the SC and thermal properties of structural thermal protection materials. In most famous works, which analyse the SC temperature and condition, a mathematical model is based on the heat balance equation composed for the SC discrete circuits and containing discrete temperature values of individual functional units, structural elements and parts of the surface.This work is aimed at defining the continuous local temperature distribution over the surface of a thin-walled shell of the SC with uneven solar radiation, including cases of moving boundaries between areas with different intensity of exposure. Application of an equilibrium temperature concept of the Sun-irradiated SC surface area allowed formulating and solving the nonlinear problems on calculation of the temperature state of the shell, which is perfectly thermally isolated on the inside surface and is non-evenly irradiated on the outside surface. The paper presents the calculated dependences for finding the temperature distribution of the shell in the vicinity of jump values of the equilibrium temperature of the surface and in the zone of the shaded band. It also considers the problem of determining the shell temperature condition at the translational and vibrational movement of the boundary between the irradiated and shaded areas.</p

Two-phase titration of dialkyl dithiophosphoric acids based on their ion pair extraction

The distribution of ion pairs formed by a number of O,O-dialkyl dithiophosphoric acids and decylpyridinium (DP) in a water-chloroform two-phase system was studied. Extraction constants (KDP) were determined. A linear correlation between logKDP and steric and hydrophobic constants of substituents at the phosphorus atom was found. Two-phase potentiometric titration can be applied to the selective determination of dithiophosphoric acids. © 1998 MAEe cyrillic signK Hayκa/Interperiodica Publishing

Mathematical Modeling of Dielectric Characteristics of the Metallic Band Inclusion Composite

Among the desirable properties of functional materials used in various electrical and radio physical equipment and devices, dielectric characteristics, including relative permittivity (hereinafter, permittivity) are of importance. The permittivity requirements can be met when a composite with a particular combination of its matrix characteristics and inclusions [1, 2, 3] is used as a functional material. The use of metallic inclusions extends a variation range of dielectric characteristics of the composite, and thereby enhances its application. The composite structure, form of inclusions, and their volume concentration has a significant impact on the permittivity.One of the composite structure embodiments is a dispersion system when in the dispersion medium (in this case | in the composite matrix) a dispersed phase (inclusions) with highly extended interface between them [4] is distributed. There can be various forms of dispersed inclusions. Band is one of the possible forms of inclusion when its dimensions in three orthogonal directions are significantly different among themselves. For such inclusion, a tri-axial ellipsoid can be taken as an acceptable geometric model to describe its form. This model can be used, in particular, to describe the form of nanostructured elements, which recently are considered as inclusions for advanced composites for various purposes [5].With raising volume concentration of metal inclusions in the dielectric matrix composite there is an increasing probability of direct contact between the inclusions resulting in continuous conductive cluster [3, 6]. In this paper, it is assumed that metal band inclusions are covered with a sufficiently thin layer of the electrically insulating material, eliminating the possibility of direct contact and precluding consideration of the so-called percolation effect [2, 7] in the entire interval of the expectedly changing volume concentration of electrically ellipsoidal inclusions. The structural model of the composite these inclusions are replaced by the uniform ellipsoidal inclusions with equivalent anisotropic dielectric characteristics that with the ordered arrangement of the inclusions leads to anisotropy of effective dielectric characteristics of the composite as a whole.There are known various approaches [1, 8, 9, 10] to the mathematical modeling that allow us to build calculated curves to determine dielectric characteristics of the composites having inclusions of different forms. When building such models, the analogy between the formulations and problem solutions of electrostatics and steady thermal conductivity [11, 12, 13, 14] can be used. Variation approaches [15, 16, 17] to estimate effective dielectric properties of the composite allow us to obtain bilateral borders between which there are their true values, and evaluate the maximum possible error occurring in using a particular mathematical model. Such borders can be set on the basis of the dual variation formulation of the problem for a potential field in an inhomogeneous solid [18]. This formulation contains two alternative functionals (minimized and maximized), taking the same extreme values in the true problem solving.DOI: 10.7463/mathm.0515.081560

Two-phase titration of dialkyl dithiophosphoric acids based on their ion pair extraction

The distribution of ion pairs formed by a number of O,O-dialkyl dithiophosphoric acids and decylpyridinium (DP) in a water-chloroform two-phase system was studied. Extraction constants (KDP) were determined. A linear correlation between logKDP and steric and hydrophobic constants of substituents at the phosphorus atom was found. Two-phase potentiometric titration can be applied to the selective determination of dithiophosphoric acids. © 1998 MAEe cyrillic signK Hayκa/Interperiodica Publishing

Local Temperature Distribution on the Spacecraft Surface under Uneven Solar Radiation

Solar radiation is the main factor to determine the thermal state of a spacecraft (SC) when it moves to the sunlit portion of the Earth orbit and moves away from the Earth. The extent of the solar radiation impact on the SC temperature state depends, primarily, on the interaction of this radiation with the surface portions of the SA body and the design elements that are placed outside the main body. To ensure the required SC temperature surfaces are used various coating and screen-vacuum thermal insulation, as well as multilayer optical solar reflectors with a thickness being in the range from tenths of a millimeter to 15 − 20 mm.When designing the SC, to predict their temperature state at various stages of operation are used mathematical models of various levels of complexity, including models related to the solution of inverse problems for determining the conditions of the thermal effects on the SC and thermal properties of structural thermal protection materials. In most famous works, which analyse the SC temperature and condition, a mathematical model is based on the heat balance equation composed for the SC discrete circuits and containing discrete temperature values of individual functional units, structural elements and parts of the surface.This work is aimed at defining the continuous local temperature distribution over the surface of a thin-walled shell of the SC with uneven solar radiation, including cases of moving boundaries between areas with different intensity of exposure. Application of an equilibrium temperature concept of the Sun-irradiated SC surface area allowed formulating and solving the nonlinear problems on calculation of the temperature state of the shell, which is perfectly thermally isolated on the inside surface and is non-evenly irradiated on the outside surface. The paper presents the calculated dependences for finding the temperature distribution of the shell in the vicinity of jump values of the equilibrium temperature of the surface and in the zone of the shaded band. It also considers the problem of determining the shell temperature condition at the translational and vibrational movement of the boundary between the irradiated and shaded areas