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  • Modeling of wind impact on a public building

    The design of energy-efficient buildings is based on the analysis of the external climatic effects on buildings for various purposes, the parameters of the air environment inside which are well defined. Climate systems of buildings should neutralize the negative impact of the external environment, in particular wind exposure. It determines both the temperature regime of the room and the purity of the air inside them. The complexity of both theoretical research and the organization of field experiments or blowing models of buildings in a wind tunnel makes it necessary to resort to mathematical modeling of the wind impact on the school building based on the StarCCm+ program. Velocity fields were obtained for different directions of wind load, the excess heat loss of the building in certain directions was determined. The possibility of conducting such studies in a wider range of initial and boundary conditions is shown.

    Keywords: aeration of residential buildings, mathematical modeling

  • Mode of generation and reception of difference frequency shear waves in a parametric profiler

    Bottom sediments (UP to) are media in which both longitudinal and shear acoustic vibrations can be present. The presence of several velocity components in bottom sediments makes it possible to excite various types of waves, both longitudinal and shear. In this paper, methods of excitation, generation and reception of difference frequency shear waves (RF) created by parametric systems in (DO) in location modes are analyzed. The analysis of their work in the DO is presented, and their comparative characteristics are given in comparison with the excitation, formation and propagation of the field of longitudinal RFCs in the DO. Prerequisites are given for the creation of a parametric profiler working using the method of excitation, generation and location of shear waves in a complex multiphase medium ""water-DO"". A block diagram is presented and the principle of operation of a parametric profiler on shear waves is described. The advantages and disadvantages of this method of location are shown. The conclusion is made about the possibility of creating and ration.

    Keywords: parametric antenna, bottom sediments, shear waves, difference frequency waves, parametric profilogaf

  • Study of changes in the local atomic structure of zinc ions in an aqueous solution in the presence of arachidic acid

    The testing of technique for modeling the local atomic structure and X-ray absorption spectra for zinc ions in an aqueous solution in the presence of arachidic acid has been adjusted. Models of the local structure of zinc with different coordination geometries are considered: planar, pyramidal, tetrahedral, and octahedral. The cases of increasing distances between the zinc ion and water molecules in the plane and in the axial direction are simulated for octahedral coordination. It has been established that the most probable change in the local structure of the zinc environment in solution in the presence of arachidic acid is the removal of water molecules from zinc ions in the axial position and their further replacement with the formation of a bond with the carboxyl group of arachidic acid.

    Keywords: arachidic acid, lipid layer, local atomic structure, X-ray absorption spectroscopy, total external reflection, zinc, biomembrane, finite difference method, monolayer

  • Analysis of the operation of the batch installation program for liquid processing of fabric with subsequent drying, written in the LD language

    The article is devoted to the control system for the process of moving textile material in an apparatus for impregnating fabrics with periodic action. The control is implemented using a programmable logic controller (PLC). We consider a program developed in the Ladder Diagram (LD) programming language that implements motion control taking into account the change in torque.

    Keywords: solution, immersion, technological process, algorithm, programming language LD

  • Оptimization modeling of an energy-saving project

    Reducing the consumption of heat resources in construction and housing and communal services is one of the key tasks solved by design engineers. The increase in the thermal protection of buildings is determined by regulatory documents, but construction customers often require it to be strengthened without any feasibility study. The objective of the study is to develop a graphical-analytical model, the analysis of which allows you to choose the most optimal combination of heat resistances of the coating (walls) and translucent structures of a particular building object.

    Keywords: energy-saving project, thermal protection of buildings, "indifference" curves, the method of the fastest descent

  • Automated non-destructive testing in the monitoring system of the technological process of bearing production

    • Abstract

    The issues of ensuring the reliable operation of bearing production on the basis of the organization of the process monitoring system (SMTP), based on the introduction of effective automated control and diagnostics of technological equipment, including processing modes and technical condition, active control of product quality in the manufacturing process, output characteristics of rings processed by the eddy current method, as well as making decisions on timely maintenance of equipment. The results of the inspection are stored in a report file generated in the eddy current device computer: information about each checked part is stored: the time of inspection, the type of part, the surface to be monitored, the number of the machine on which the part was processed. The results of eddy current control serve as the basis for monitoring the dynamic characteristics of the equipment by vibroacoustic vibrations. Based on the results of the control within the framework of the SMTP, a decision is made on the quality management of processing. The introduction of SMTP provided a significant reduction in ring defects in terms of grinding quality up to 2-3 % and increased operational reliability of bearings.

    Keywords: grinding process monitoring, bearing rings, dynamic machine quality, active control, eddy current control, ring quality

  • Existing Ways to Formalize Fuzzies in Transport Processes

    The lack of information about the conditions for the implementation of transport processes does not allow building mathematical models that operate with extremely accurate input data. Therefore, methods are being developed that formalize input uncertainties for constructing mathematical models of transport processes. To describe uncertainties, along with static, stochastic and interval approaches, methods based on fuzzy sets are actively used. The generalization of the belonging of the element, presented by Zadeh, allowed blurring the boundaries of the set. The blurring of the boundaries of the sets allows one to formalize insufficiently complete, in an informational sense, judgments and facts for the purpose of the subsequent use of this information in the construction of mathematical models. To identify formal approaches to working with uncertainties, an analysis of foreign periodicals in recent years has been carried out and two well-known approaches have been identified. The first is based on the theory of fuzzy sets - the generalized concept of belonging of an element to a set, leading to blurring of the boundaries of the set. The second approach involves describing fuzziness using a hierarchy - a family of ordered crisp sets [1]. Within the framework of the first approach, the authors have identified five ways of formalization. The first includes fuzzy sets (numbers) with different n-gonal forms of the membership function. The second consists of intuitionistic fuzzy sets (numbers) with n-gonal membership functions. The third contains heterogeneous fuzzy sets of type 2. The fourth represents non-standard fuzzy sets (oscillating, Pythagorean, etc.). The fifth method is a combination of spaced fuzzy numbers, intuitionistic spaced fuzzy numbers, and the like. References are given to sources containing a description of formalization methods and their application in solving some fuzzy transport problems, possible directions of research on the considered topics are formulated.

    Keywords: fuzzy transport routing problem, optimization, fuzzy methods, fuzzy numbers, fuzzy sets, heuristic algorithms, hybrid algorithms, transport processes

  • Simulating of an optical vector analyzer with high-resolution and high-accuracy based on optical double-sideband modulation and stimulated Brillouin scattering

    The article discusses an optical vector analyzer with high resolution and high accuracy based on optical double-sideband modulation and stimulated Brillouin scattering. A model of an optical vector analyzer is presented.

    Keywords: optical vector analyzer, double-sideband modulation, stimulated Brillouin scattering, fiber Bragg grating with phase shift, simulation, Optisystem

  • Seasonal Winter’s model with the linear growth of statistical cost

    • Abstract

    The article deals with building a seasonal model with a linear growth of the Winter’s statistic value, on the basis of which the parameters are calculated: the customs value index and the weighted average rate, which are the composition of the calculation formula of customs payments. To build the model, the monthly data of the customs statistics on imports of 28 commodity group “Products of inorganic chemistry; inorganic or organic compounds of precious metals, rare earth metals, radioactive elements or isotopes” of the Customs Nomenclature of the external economic activity of EAEU from 01.01. 2018 up to 31.12.2020 are used in the region of activity of the Southern Customs Administration.

    Keywords: time series, econometric modeling, forecasting, adaptation parameter, seasonality coefficients, adaptive model

  • Study of the operation of a local recirculation diffuser in an office space during the period of operation

    a study of a ventilation system with a local recirculating diffuser was carried out. A three-dimensional model of the office space has been built. Using the STAR-CCM + hydrodynamic computing complex, a numerical simulation of the ventilation system has been performed. The calculation results are analyzed, the advantages of the investigated system are given.

    Keywords: ventilation systems, local recirculating diffuser, indoor air quality, energy saving, numerical simulation, STAR-CCM +

  • Bayesian approach in justifying the number of necessary experimental measurements in environmental quality control

    Based on the Bayes approach, a representative number of experimental measurements was determined when assessing the quality of the environment, in particular, when monitoring the quality of the atmosphere and checking the compliance with the standard for the accumulation of solid municipal waste

    Keywords: Bayesian approach, quality control, experimental measurement, a priori data, a posteriori data, distribution density

  • Тechnical and economic justification method for energy-saving investment project

    Reducing energy consumption in the design, installation and operation of engineering networks is implemented in the process of implementing investment construction projects. An energy service contract, like any economic agreement, requires a feasibility study. When strengthening the thermal protection of a building, it is necessary to determine both the design of the fences and translucent structures, and the payback period of the investment. The objective of the research is to develop and analyze a mathematical model of heat losses depending on the characteristics of the resistance to heat transfer of walls, windows and balcony doors. Classical dependencies do not allow applying standard mathematical analysis procedures. It is proposed to use a power function that assumes the availability of differentiation. The paper substantiates the form of such a function and provides an extended analysis of the effect of changes in the resistance to heat transfer of building structures on the transmission heat losses of a building, which allows arguing for the adoption of optimal technical and economic decisions.

    Keywords: energy-saving construction project, thermal protection of buildings, indifference curves, mathematical model of heat loss

  • Assessment of the state of biologically active filter material in the working area of closed sewage treatment facilities

    The paper presents studies of the state of biologically active filtering material - vermicompost in the working area of ​​the aeration station at closed sewage treatment plants with an increased concentration of sulfur dioxide. The assessment of the filtering sorption properties was carried out using bioindication methods, namely, germination of test seeds under conditions of an increased content of sulfur dioxide. The bioindication method is considered fast and accurate, it allows to obtain reproducible results.Oat seeds, wheat seeds - representatives of monocotyledonous plants, as well as radish seeds - a dicotyledonous plant, were used as test seeds, as they are highly sensitive to harmful effects. The experiment took place in four stages with different time intervals. The indicator is the average length of development of the root system in the tested water compared to the control. The results showed that 60% of normal germination was recorded in monocotyledonous seeds, and 90% of normally germinated seeds were recorded in dicotyledons. According to the well-known method, the non-toxic properties of vermicompost was assessed based on the lengths of shoots and seed roots, which can be used as a load in installations for the biochemical purification of gases emitted into the air of the working area from closed wastewater treatment facilities. Such an installation can be a biofilter. Thus, the thickness of the load, the height of each of its constituent layers, affects the degree of its efficiency.

    Keywords: sulfur dioxide, bioindication, closed treatment facilities, waste water, test seeds, germination of seeds, vermicompost

  • Modern methods and algorithms for solving fuzzy distribution (transport) problems, reflected in foreign literature

    The article discusses the work of foreign authors in the field of solving fuzzy distribution (transport) problems. To solve such problems in real conditions, it is rather difficult to formalize all parameters in the form of definite numbers, therefore, the field of solving fuzzy distribution (transport) problems attracts wide attention of scientists and experts, provoking numerous successful studies. To solve distribution (transport) problems, when considering the current state of foreign literature, the main approaches have been identified, consisting in the use of pentagonal, hexagonal, octagonal fuzzy numbers, ranking, intuitive fuzzy environment, as well as the Pythagorean approach. Now it is becoming more and more important to use inaccurate data in real transportation problems. The listed approaches to solving distribution (transport) problems give a certain effect in comparison with the existing ones, therefore it is necessary to investigate solutions of fuzzy distribution problems using modern approaches and methods.

    Keywords: fuzzy transport routing problem, optimization, fuzzy methods, fuzzy numbers, heuristic algorithms, hybrid algorithms

  • Improving the thermal protection of building enclosing structures

    The results of the analysis of quality parameters of building materials used for insulation of walls of residential buildings are presented. The problem of increased consumption of thermal energy for heating needs is identified, the solution of which is to increase the thermal characteristics of the enclosing walls of buildings by means of their insulation and protection by the system of a hinged ventilated facade.

    Keywords: Hinged ventilated facade, thermal characteristics, influencing factors, energy efficiency