Volume 6, Nº 1 (2019)

The article reviews theoretical and practical aspects of the analysis of friction in rotating pairs. The conceptual framework for the study of friction is considered using the example of a friction pin in a bearing. A practical experiment involves calculating the efficiency of cardan transmission through the work expended on the resistance of friction forces in the kinematic pairs of cardan joints. Mathematical dependences determine the elementary work of the friction forces in the kinematic pairs of a single universal joint, the efficiency of the articulated mechanism and the translational kinematic pair in the splined joint of the universal joint.

Task. This article proposes the development of a new version of the method of electronic speckle interferometry and calculationand experimental analysis of the VAT perspective full-scale aircraft with complex VAT and new materials.Summary. An important feature of speckle interferometry is the use of electronic photography of a particularly thin, “granular” structure of light reflected by a diffuse object in laser light. With the use of electronic speckle interferometry, a new generation system for measuring stresses in elastic bodies and structures was created, which combines the ideas and methods of holographic interferometry. In addition to the study of stresses, this system allows to solve other problems: the places of application and the magnitude of the loads acting on the elastic body, the stresses in thin films and the connections of their mechanical characteristics with stresses, the distributed and local inhomogeneities of the body structure, the microcracks and internal bundles, the delamination of coatings and deformation prerequisites for their occurrence, etc. Practical significance. The use of electronic speckle interferometry is an important and promising method for the study of aircraft structures with the identification of stress concentration zones and the determination of physical and mechanical characteristics of various materials, this problem is considered in this article.

Simulation of amorphous metals (Al and Ti) and their contact are carried out by methods of the density functional theory. It is shown that amorphous metals can demonstrate approximately the same cohesive energy that crystalline metals. Densities of electronic states were calculated and compared for amorphous and crystalline metal states. Values of adhesion energy for contacts “crystal - crystal”, “crystal - amorphous system”, and “amorphous system - amorphous system” were compared.

The article provides an analysis of the main areas of resource and energy conservation in the petrochemical complex of Russia. On the basis of statistical data, trends in this field of research are presented, allowing to determine the positive and negative factors of the implementation of resource saving programs in petrochemistry. Based on the cluster analysis for the subjects of the Volga Federal District, groups of regions were identified in terms of the energy intensity of the gross regional product and the electrical equipment of labor. The results of the analysis can be used in the development of regional resource-saving programs in the petrochemical complex.

Background. The paper is devoted to experimental verification of the possibility of the influence of minor difference between supported nanocatalysts within their carriers’ structure on their functional characteristics, in particular, on the calculated sizes of the active fractions. The oscillatory pattern of CO and hydrogen oxidation, observed in some cases in the presence of platinum metals’ containing nanoparticles, suggests the presence of dissipative structures. It’s known that systems possessed of high complexity (according to Von Neumann), in particular, autocatalytic hypercycles are capable of self-organization. Another sign of such systems’ presence may be a critical influence of minor changes in structure and/or composition on their characteristics. The possibility of such an effect has been verified experimentally: a series of palladium-containing nanocatalysts on activated carbon fibers, differing in particle size distribution, have been synthesized. Carbon fibers obtained from two different precursors were used. Samples from each batch were subjected to reductive treatment with hydrogen at a metered ratio. The boundary sizes of the active fractions are calculated, as well as the activity in the reaction of low-temperature oxidation of CO, at various depths of reduction. Since, for chemically sufficiently inert carbon fibers, a change in the nature of the precursor to the final nanosystems can be considered an insignificant influence factor, a significant effect of such an effect can be considered as confirmation of the hypothesis of the origin of self-organizing systems.Methods. All calculations were made by using MS Office Professional 2013. A series of palladium nanocatalysts on activated carbon fibers “Busofit Carbopon-Activ” with active surface of 1300 m2/g and Mtilon-M with an active surface of 2700 m2/g was prepared; sizes of nanoparticles varied by choosing modes of drying after application solutions with ions Pd2+. The initial reaction rate was measured by gas chromatography from CO concentrations’ decreasing.Results. The calculation of boundary sizes of nanosystems’ active fractions obtained using the Ball Painting Model showed that carbon fibers’ structure has a significant impact on these dimensions. In nanosystems on Carbopone in comparison with nanosystems on Mtilon-M, not only is the activity shifted towards particles with a smaller diameter, but also a significant narrowing of the size range within which nanoparticles retain activity. Recovery leads to a continuous narrowing of this interval, and therefore the total activity becomes lower with increasing content of the recovered phase. The catalysts applied to Mtilon-M are characterized by a wide size distribution, with unusually large particles showing activity.Despite the insignificant differences in the structure of the carrier, the characteristics of nanosystems differ significantly. This suggests that more likely are processes with the formation of autocatalytic hypercycles, otherwise one would expect that particles of the same size would be active regardless of the nature of the carrier.Conclusion. Minor changes in the structure of the carrier matrix lead to significant differences in the characteristics of nanocatalysts - the boundaries of the active fractions are mutually shifted, and the interval of the boundary sizes can be both wide enough and extremely narrow. This is consistent with the hypothesis of the formation of autocatalytic hypercycles, the level of complexity of which suggests that they are self-organizing.Implementation opportunities. High toxicity, lack of color and smell, low adsorption and chemical passivity of CO make it one of the most dangerous toxins. The removal of CO in practice is seriously difficult, and the use of nanocatalysts for life-support and respiration systems is practically non-alternative in this aspect. A reliable method of obtaining self-organizing high-performance nanosystems capable of removing CO under room conditions would be used to clean the atmosphere of closed living spaces - in cars, spaceships, submarines, in industrial workshops, and others. Considering that for almost all other gaseous toxins, with the exception of CO, robust removal systems have been developed, filling this gap will allow creating universal filters for life support systems.Social consequences. Work in this direction can be a solution to a number of social problems, including health safety while in traffic jams, especially for risk groups.Originality/value. Proof of hypercycles’ formation at a high level of complexity capable of further self-organization, and their careful study is of great theoretical importance for understanding the possibilities that open up for non-equilibrium dissipative systems - it is possible that they can be compared with questions about the origin of life and the evolution of hypercycles in nature. The study of the influence of the nature of carbon fiber precursor on the behavior of hypercycles seems rather unexpected, but nevertheless remains fruitful.

The article discusses the possibility of representing fuzzy knowledge in complex systems by means of tensor methodology. The tensor methodology is considered as a general system theory method used to analyze complex systems. The method is the result of applying the apparatus of tensor algebra in solving problems of the general theory of systems. A fuzzy logic apparatus is used to represent fuzzy knowledge in a complex system. Using the example of building fuzzy sets on a certain domain, a method is proposed for obtaining a tensor from elements of a fuzzy set and a membership function. The results are illustrated by the description of the world of fuzzy objects of a complex system, which includes the representation of objects and the relations between them. The advantages of using tensor methodology to represent fuzzy knowledge in complex systems are noted.

A new method for calculating the optical geometrical and optical power characteristics of the formed focal spot of mirror-concentrating systems from individual facets with real accuracy and adjustment characteristics and concentrator zones with a complex configuration is proposed.