Unidirectional convective flows of a viscous incompressible fluid with slippage in a closed layer

An exact solution describing the flow of a viscous incompressible fluid in a closed horizontal layer is obtained in view of the Navier slip condition and the inhomogeneous pressure distribution on one of the layer boundaries. The principal possibility of velocity field stratification and the dependence of the number of stratification points on the slip length are demonstrated. © 2019 Author(s)

Rotational imaging optical coherence tomography for full-body mouse embryonic imaging

Optical coherence tomography (OCT) has been widely used to study mammalian embryonic development with the advantages of high spatial and temporal resolutions and without the need for any contrast enhancement probes. However, the limited imaging depth of traditional OCT might prohibit visualization of the full embryonic body. To overcome this limitation, we have developed a new methodology to enhance the imaging range of OCT in embryonic day (E) 9.5 and 10.5 mouse embryos using rotational imaging. Rotational imaging OCT (RI-OCT) enables full-body imaging of mouse embryos by performing multiangle imaging. A series of postprocessing procedures was performed on each cross-section image, resulting in the final composited image. The results demonstrate that RI-OCT is able to improve the visualization of internal mouse embryo structures as compared to conventional OCT

Inhomogeneous Couette flows for a two-layer fluid

The paper presents a new exact solution to the Navier–Stokes equations which describes a steady shearing isothermal flow of an incompressible two-layer fluid stratified in terms of density and/or viscosity, the vertical velocity of the fluid being zero. This exact solution belongs to the class of functions linear in terms of spatial coordinates, and it is an extension of the classical Couette flow in an extended horizontal layer to the case of non-one-dimensional non-uniform flows. The solution constructed for each layer is studied for the ability to describe the appearance of stagnation points in the velocity field and the generation of counterflows. It has been found that the flow of a two-layer fluid is stratified into two zones where the fluid flows in counter directions. It is also shown that the tangential stress tensor components can change their sign. © Authors, 2023

Features of selecting boundary conditions when describing flows of stratified fluids

The article discusses the selection of boundary conditions at the boundary between adjacent layers in a stratified viscous incompressible fluid. It is shown that the "continuity condition + differentiability condition" pair traditionally used in many disciplines gives physically unjustified properties of the resulting exact solution for the velocity field. Although the condition for the differentiability of velocities is close in mathematical form to the stress continuity condition (by virtue of Newton's law), in terms of physics, taking these conditions into account gives fundamentally different properties of the exact solution of the Navier-Stokes system of equations. It is shown that the consideration of the "the velocity field continuity condition + the stress field continuity condition" pair is more adequate to the physics of the process, which is consistent with the hypothesis of continuity. © 2021 Elsevier B.V.. All rights reserved

Human Rights Risks in the Constitutions of the American Federal States

The article presents the results of a comparative legal analysis of the constitutions of American federal states (Argentina, Brazil, Venezuela, Canada, Mexico, and USA) with a view to identifying the norms that minimize human rights risks. The examination depended on an argumentative way to deal with the revelation of legitimate wonders and cycles utilizing general logical (precise and consistent strategies, investigation and amalgamation) and explicit logical techniques. The declared axiological, functional, and institutional parameters are fully set only in the Constitution of Venezuela. Other constitutions that consider the objective specifics of the historical development of countries reflected the desired formulations in the framework of the axiology of individual rights and freedoms; prohibition of slavery; judicial protection of individual rights; isolation of a special human rights institution, etc. The objectives of the study led to the use of special legal methods. Thus, the comparative legal method contributed to the identification of resources and means of minimizing risks to human right advocacy in the foreign constitutions. The novelty of this research is identifying the norms that minimize human rights risks

The Influence of Shear Stresses on the Velocity of Isothermal Flow of Viscous Two-Layer Fluids

The report presents the new exact solution of the Navier-Stokes equations for describing the isobaric flow of a viscous two-layer incompressible fluid, which layers have different properties (thickness, density, viscosity). The main attention is paid to the analysis of the velocity field

Interdisciplinary syndromic description of the structure of defect in children with trite dysarthria

В статье рассматриваются результаты нейропсихологического и лингвологопедического исследования особенностей дошкольников со стертой формой дизартрии.Modern trends in pedagogical and defectological education indicate a continuous increase in the number of children with various speech disorders and the complexity and mosaic nature of their defect structures, which affect the formation of the child's personality. Often, speech therapists find it difficult to formulate a logopedic conclusion and note an insufficient competence level to determine the primary, secondary and tertiary levels in the structure of the defect, and the difficulty in describing the syndromic picture of speech disorder

Human rights risks in the constitutions of the American Federal States

The article presents the results of a comparative legal analysis of the constitutions of American federal states (Argentina, Brazil, Venezuela, Canada, Mexico, and USA) with a view to identifying the norms that minimize human rights risk

Peculiarities of acid-base properties of peat formed in various agroclimatic zones of the Altai mountainous region

The results of the study of acid-base indicators of peat in the Altai mountainous region are presented. The natural factors that in the aggregate determine the peculiarities of the physicochemical properties of mountain peat of different agro-climatic zones of the Altai Mountains have been revealed. The variation in the acid values, total absorbed bases, adsorption capacity and the degree of saturation of raised-bog, transitional, fen peat, the number of exchangeable ions Са2+ and Mg2+ has been estimated. The interrelation among these indicators has been presented. For the first time, regression equations of the relationship between exchangeable acidity рНKCl and the degree of peat base saturation V, between total absorbed bases S and the degree of peat base saturation V have been obtained using nonlinear regression analysis. The adequacy and stability of the developed models have been verified. The calculated mean errors of approximation of regression models characterise the high accuracy of the forecast and are indicative of a good selection of models for the initial data