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Numerical modeling of a flow around a symmetrical thick drop-shaped airfoil in a non-stationary formulation was carried out at Reynolds numbers Re = 10⁴ ÷ 10⁵ and in the range of angles of attack α = –10 ÷ 10°. The calculations were performed in the approximation of the unsteady Reynolds-averaged Navier-Stokes equations (URANS) using the implicit large-eddy method (ILES). In the URANS approach, the position of the laminar-turbulent transition was determined based on the models k–kl–ω, k–ω–γ–Re_θ (Menter model) and (k–ω)-SST models with a given laminar flow region. It is shown that the position of the laminar-turbulent transition region has a significant impact on the flow structure and aerodynamic characteristics of the airfoil. Comparison of the results obtained using the ILES approach with experimental data showed that they are in good agreement. URANS calculations did not allow obtaining results consistent with experimental data. Fixing the laminar-turbulent transition point in the URANS calculation in some cases made it possible to correct the results.

Ceramic composites based on B₄C with a mole fraction of CrB₂ 0-30% were obtained by reactive hot pressing of a mixture of B₄C, Cr₂O₃, and nanofibrous carbon at a press force of 17.5 MPa, a temperature of 2000 °C and an exposure time of 10 min. The possibility of the chemical reduction reaction of metal oxide with boron carbide during hot pressing was studied. During the synthesis of CrB₂, the density of B₄C was found to increase due to the formation of the CrB₂-B₄C eutectic liquid phase. The relative density of all B₄C-CrB₂ composites obtained under these conditions exceeds 90%. The dependences of the microhardness and elastic modulus of samples on the concentration of the plastic phase were obtained. The dependence of the elastic modulus of the heterogeneous material on the volume fraction of chromium diboride taking into account porosity was determined by sequentially using the Reuss and Voigt averaging schemes

A method of transition from the three-dimensional piezoelastic problem for a composite material to the one-dimensional problem for a piezoelastic beam is presented. This is done using an asymptotic method of homogenization based on the separation of fast and slow variables in the solution. A special feature of the problem is the presence of two small parameters, one of which characterizes the microstructure of the composite material, and the other the cross-sectional size. Averaged relations describing the piezoelastic beam and fast correctors were obtained. Their joint use makes it possible to correctly describe the total stress-strain state of the initial three-dimensional body. The proposed method is suitable for solving the three-dimensional problem of deformation of an extended bodies with an arbitrary periodic structure and new problems (e.g., the torsion problem) that have no analogues in the theory of piezoelastic plates.

The stress-strain elastic field in a square array of N non-overlapping circular inclusions is described by approximate analytical formulas. In particular, soft inclusions are studied by an asymptotic analysis. The case with N = 1 yields a regular square array of disks of radius r embedded in an elastic matrix. The computations of Natanzon and Filshtinsky are based on an infinite system of linear algebraic equations solved by the truncation method. The infinite system determines the Taylor series coefficients of the Kolosov-Muskhelishvili complex potentials. A method of functional equations is used to write the series coefficients in symbolic form up to terms of the order of O ( r ^2s) at a fixed value of s . Approximate analytical formulas for local elastic fields are derived.

The article begins a series of final author’s publications designed to evaluate Descartes’ contribution to the formation and development of the philosophy of the Modern Era. The subject of concern directly in this article is the totality of the components of Descartes’ worldview, scientific and philosophical positions in its integrity and structural specifics. Ten such components are identified, and six of them are worthy of special mention considering their subsequent primary development in the philosophy of the Modern Era. These are materialistic, objective-idealistic, subjective-idealistic, skeptical and irrationalistic components, as well as one more, which there is no reason to describe as directly and consistently dialectical, but which is nevertheless represented in Descartes by his concrete steps to form one that. Focusing here not only on these six components, but on their totality also makes sense. To be exact, this clearly shows that in Descartes, they form a unity in which at least the first six both exclude and condition each other. Whereas, in subsequent modern European philosophers each of this components is present primarily as a separate line, declared as perhaps the only acceptable and worthy of efforts to develop it. So, focusing on the total picture of Descartes’ views makes clear the structural integrity of the entire modern European philosophy in all the diversity of its main components.

The article studies the heuristic capabilities of the law of the negation of negation and related categories for revealing the patterns of the growth of scientific knowledge. Based on the history of natural science, it is shown that the struggle of alternative concepts can be presented in the light of this law as completed cycles of transition from the initial thesis through several antitheses to the final synthesis, which can subsequently become a thesis within the framework of a new cognitive cycle. According to the conducted analysis, the authors formulate methodological recommendations addressed to a wide range of researchers and aimed at increasing the effectiveness of any creative activity.

The object of this study is the principle of least action (PLA) taken in the dialectical unity of various aspects of its manifestation in philosophy and science. The ways and means of PLA influence on the formation and implementation of the sustainable devel-opment strategy are also identified. Methodologically, the research is based on the ideas of classical philosophy, the ideas of L. Wittgenstein, the statements of the French epistemological tradition, and J. Derrida’s postmodernist principles of deconstruction. The methodological significance of PLA is substantiated as a precedent of fundamental ontology, which will be able to strategize for evolutionary adaptation and socio-ecological optimization.

The article examines three types of surveyability: global, local and “mesoscopic”. The discussion of surveyability relates to computer proofs. The third type of surveyability, viz. “mesoscopic” surveyability, involves grasping the elementary steps of a proof in a group and relies on geometric intuition. Also, geometric intuition plays an important role in the concept of rigor as local validity. The article compares “mesoscopic” surveyability and the concept of rigor as local validity.

К. Barad proposes agential realism as a unified approach to natural and social phenomena. The position is inspired by quantum mechanics and, in particular, the phenomenon of quantum entanglement. Barad also sees similarities between her approach, N. Bohr’s view and C. Rovelli’s relational quantum mechanics. In our opinion, agential realism is a kind of ontological correlationism, and not realism. The analogy with the approaches of Bohr and Rovelli is only partial. Agential realism is a wrong interpretation of quantum mechanics. It is also unsuitable for social theorizing, for which considering the context sensitivity of ontology is fundamental. As an alternative, we propose contextual quantum realism (CQR), which rejects substance dualisms (as Barad does) but at the same time accepts the categorical dualism of the real and the ideal. Our approach also allows for a better understanding of Bohr’s position and correcting Rovelli’s relational quantum mechanics.

The work is aimed at substantiating the applicability of H.-G. Gadamer’s hermeneutical ideas to the philosophical and methodological analysis of geological knowledge. Arguments are given in favor of the fact that cognitive practices in geology are more closely related to the hermeneutic cognitive procedures of human history than to the cognitive procedures of experimental physics, focused on the search and formulation of general laws. At the same time, Gadamer’s hermeneutical ideas are adapted to the context of geological knowledge.