卷 6, 编号 2 (2019)

This article presents a qualitatively new developed technology of out-of-band registration of speckle holograms in the study of deformations in the concentration zone on samples with holes. Summary. One of the most important aspects of speckle-holographic interferometry is the quality of the resulting speckle-hologram, which largely determines its diffraction efficiency. In this case, the improvement of diffraction efficiency in solving practical problems is carried out through the selection of the developer of photographic plates, the installation of a certain exposure time and the choice of methods for processing photographic plates. However, in practice, there are often problems of obtaining the maximum diffraction efficiency of holograms. We made a choice of developer, exposure time, as well as methods of photo processing of speckle holograms in colliding beams in the process of practical experiment. Practical significance. The technology of out-of-band registration of speckle holograms described in the article can be used in the process of research of SSS of full-scale aircraft structures in areas of stress concentration, as well as their detection during industrial full-scale tests.

This article presents the results of the study of activating oxide fluxes effects on the energy efficiency of the TIG welding arc (A-TIG) influence. This efficiency was estimated by the amount of energy spent by the arc (q) at the depth of penetration (P). It is revealed that the arc energy efficiency factor “Kepac” can be used as an indicator of the influence of arc energy on the efficiency of penetration of the welded metal, which is determined by the ratio of spent energy per unit of depth of penetration (q/P) at TIG and A-TIG welding. In accordance with the results of the research, it is observed an increase of the energy efficiency on the welding arc penetration capability of all individual oxides used as fluxes in A-TIG welding is observed. Among them, the greatest energy efficiency of the arc process on the penetration of CrNi18-10 steel is observed when oxides such as TiO2, SiO2, Cr2O3 and Co3O4 are used.

Purpose. The article presents a laboratory setup and a measuring system of oscillations of a fixed wire with a transverse impact.Findings. This measuring system can be used to determine wire displacements from 1.5 µm with a time resolution of 5 ns.Practical meaning. The laboratory setup will allow experimental studies of the reaction of the wire and the frozen ice tube to a mechanical shock by an inductor, the speed and energy of which can be an order of magnitude higher than that of a pendulum. Originality/value. Described installation for the study of the destructive effect transmitted to the ice indirectly, through a bump,mounted on the wire.

The article is devoted to the currently actual problem of the development and dynamics of the population in urban education from the point of view of spatial-dynamic approximation. The population is divided into different groups according to their economic and individual characteristics. For example, the population can be classified according to genetic and phenotypic characteristics, according to the level of income or education. The question of the peaceful and effective interaction of groups with each other is one of the most important tasks within any urban type of education. The author describes the problem of the interaction of two groups at a qualitative level using a system of two non-stationary nonlinear differential equations of diffusion type. Particular attention is paid to the disclosure of the numerical solution scheme of the selected model: the use of an explicit (in time) difference scheme of the “predictor-corrector” type has been analyzed in detail. In addition, the author conducts a series of computational experiments taking into account the selected assumptions regarding two specific groups of the population. Separately, the solution of the stochastic case and the features of its software implementation are considered. Based on the results of the study, the possibility of the applicability of the new approach to the problems of urban studies is substantiated. This work is the first step in the implementation of a program of using spatial economics to describe real processes in urban formations.

The method of constructing a mathematical model of the power supply system of a promising long-haul passenger aircraft in the SimInTech software system is Considered. The results of modeling the four-channel system of generation and distribution of AC power under normal operation are presented, the features of mathematical modeling of the power supply system are shown.

The article describes an approach that allows to formally describe the arising uncertainties in linear optimization problems. The generalized parametric alpha-level method of lambda-continuation of the fuzzy linear programming problem is considered. The model offers two methods that take into account the expansion of the binary fuzzy ratio (“strong” and “weak”). After the condition is formed taking into account the incoming quantities in the form of fuzzy numbers (the objective function and the system of constraints), the optimal solution (the value of the objective function) for each alpha and lambda is calculated using the simplex method implemented in Mathcad. On its basis, a mathematical model is built that will take into account the random values of alpha and lambda with a uniform distribution law. The paper presents a description of the simulation study, which confirms the conclusions about the possibilities of the method. Using the proposed theory, the decision-maker receives more information showing the behavior of the system with small changes in the input parameters to make more informed conclusions about the choice of financing of an investment project. The developed method of simulation of fuzzy estimation can be applied to other economic models with the appropriate necessary modification, for example, to assess the creditworthiness of the enterprise.

In this paper, we consider a method for constructing new permutations from the original permutations of a finite field, which generalizes the results from [1] how to increase the dimension of regular systems of functions. For constructed substitutions, a linear characteristic is calculated.

The article describes the issues of creating a cockpit of a promising aircraft using a search modeling stand with the aim of obtaining an ergonomic evaluation of crew workplaces and the information and control field of the cockpit in the early stages of design. It describes the requirements, the structure of the stand and the tasks solved with the help of it.

The article considers a solar air heater with a heat sink of metal shavings and the possibility of increasing efficiency by changing the location of the heat sink inside the structure. And also considered to improve the efficiency of the corrugated surface of the heat sink due to the angle of the corrugations. An analytical formula for calculating the radiation transmittance through the form of metal shavings is proposed.

A new method of calculation and accelerated regulation of optical-geometric and optical-energy characteristics of the formed focal spot of mirror-concentrating systems from individual facets with high accuracy and alignment characteristics and concentrator zones with a complex configuration of a Large Solar Furnace was developed

A report is presented about progress in the understanding of the properties of bi-metallic nanoparticles, their interaction with surfaces subsequent to low energy slowing down and the properties of nanostructured materials formed with these particles. A nanoparticle contains from a few atoms for the smallest ones to several thousand for the largest ones considered here. The properties of an atom result from quantization and the same is true for the molecules they form. The same is thus true for the smallest nanoparticles. At the other edge, many of the properties of macroscopic materials are well described by a classical approach and nanoparticles appear as objects at the fringing field between quantum and classical behaviors. In the study of their properties, using either a quantum or a classical approach, atomic scale methods appear as naturally well-suited. Atoms are considered as individual objects interacting via their outer shell electrons only. However even with such an approximation, solving the Schrödinger equation becomes quickly prohibitively heavy as the number of atoms involved increases. For the heaviest elements, relativistic effects make the problem even heavier.