This article presents a method for determining the parameters of oil-producing enterprise equipment under conditions of information uncertainty based on cluster analysis using the k-means method. Cluster analysis is performed based on identifying internal structures and patterns based on the data of installed electrical equipment. Proceeding form this, the most probable values of insufficient equipment parameters are selected. Based on the results of cluster analysis, an algorithm for determining the parameters of electrical and electromechanical equipment of electric centrifugal pump units is developed with allowance for the factors that affect the key parameter of unknown equipment. The developed method will allow indirectly assessing the energy efficiency in any operating mode of equipment in oil-lifting sites.

An algorithm has been proposed for optimizing the consumption of electrical energy in the electrical complex of an oil-production enterprise within one cluster of wells. The implementation of an algorithm is possible by implementing the developed structure of a unified, centralized control scheme. The control structure will allow you to quickly integrate and test the latest algorithms for energy-efficient methods of controlling oil production units without the risk of prolonged equipment downtime and disruption of technological process. The proposed control method will make it possible to quickly adjust technological maps of oil production to ensure the desired results of oil production while reducing the total electricity consumption at the balance sheet boundary.

The applications of hub location in the construction industry's supply chain are indicated in this review. The primary advantages of hub networks stem from (i) lower movement (i.e., transportation or transmission) costs from consolidated flows that exploit economies of scale, especially between hubs, (ii) reduced costs from establishing a sparser network to connect many dispersed origin-destination (O–D) pairs, and (iii) better service from allowing more frequent connections due to the consolidated flows. The research describes the background in the supply chain, especially the construction industry, as well as the background of hub location issues with a brief introduction. The research gap related to the application of hub location problems in the construction industry's supply chain is specified by reviewing and comparing research. Given the framework for a wide range of hub location problems and models and the supply chain in the construction industry, the service time and cost variables have been a common chapter between the two areas. The proposal to use a simple Hub Center Problem model with a service time variable due to the similar application of this type of model in the research background in a similar supply chain is presented in the final section.

A brief overview is given of the standards required for serial production of LAN cables of various categories. It is shown that for twisted-pair LAN cables category 5e and higher, it is necessary to complete development of the procedure for measurement of key frequency responses (in particular, determining the frequency dependence of the actual value of wave resistance), regulated by the operative GOST R 54429-2011. The reason for the errors of network analyzers are revealed as the effect of the extended cutting section; and the hypothesis that it is impossible to eliminate it within the framework of existing models is substantiated. A hypothesis is formulated about the interference of signals reflected from the beginning of the twisted pair and from the place of its entry into the shell as the primary reason for the distortion of the results of practical measurements. Experimental data confirming the correctness of the proposed assumptions is presented. Modernization of the calibration procedure of the measurement system is proposed, without updating the hardware and software of the vector network analyzer (VNA). The required result is achieved by using a distributed calibration load, individualized for each type of cable, based on a segment of a twisted pair that is manufactured in a production laboratory. It is shown using calculated data and measurement results that the use of such a load reduces from 14 to 3

The article explores the methodology of complex analysis of ways effective management of production systems. A generalized approach to the decomposition of modern digital systems based on physical control actions, signal transmission ways and generalized principles of control system construction is investigated. Additional control physical effects act as one of the target factors of intensification. A generalized formulation of the problem of optimal control of complex multistage processes is proposed, considering the main perturbing processes and a piecewise-constant functions of the local tasks. Methods of search of new technical solutions by means of the morphological analysis as the tool of systemic and cybernetic approaches in scientific research are proved. Intensification of control systems is aimed at increasing their economic efficiency as a result on search for technological resources, of purposeful influence traffic flows and so on. The formulated principles of hierarchy, selectivity, openness, and mutual consistency, which are not exhaustive, but are closely interrelated and determine the application of methods of hierarchically interconnected control, considering the intensification of systems when choosing the control factors, as well as of physical impacts. The proposed approach leads to the possibility of intensification of high-tech industrial production processes and transport systems, and so can be implemented in the process of their technical operation. Identification of possible physical effects, synchronization of signals is a key factor in using the proposed methodology. The modular system of transport companies allows for flexible and transparent management of the system as a set of individual elements. Generalized goal-oriented models are applicable in many branches of industrial production, including the intensification of transport systems and business processes of enterprises.

The properties, application, and methods for producing chromium and zirconium carbides are considered. These carbides are oxygen-free refractory metal-like compounds. As a result, they are characterized by high values of thermal and electrical conductivity. Their hardness is relatively high. Chromium and zirconium carbides exhibit significant chemical resistance in aggressive environments. For these reasons, they have found application in modern technology. Chromium carbide is used mainly as component of surfacing mixtures to create protective coatings that resist intensive abrasive wear, including at elevated temperatures (up to 800 °C) in oxidizing environments. This compound is also used in the manufacture of tungsten-free hard alloys and carbide steels. Chromium carbide, along with vanadium carbide, is used as a grain growth inhibitor in WC – Co hard alloys. Powdered zirconium carbide can be used to polish the surface of items made of ferrous and non-ferrous metals. The properties of refractory compounds depend on the content of impurities and dispersion (particle size). To solve a specific problem associated with the use of refractory compounds, it is important to choose the right method for their preparation, to determine the permissible content of impurities in the initial components. This leads to the existence of different methods for the synthesis of carbides. The main methods for their preparation are: synthesis from simple substances (metals and carbon), metallothermal and carbothermal reduction. Plasma-chemical synthesis (vapor-gas phase deposition) is also used to obtain carbide nanopowders. A characteristic is given to each of these methods. Information on the possible mechanism of the processes of carbothermal synthesis is presented.

A reflectance-schlieren technique, enhanced by the stepped gradient filter, is applied for accurate measurements of the map of thin liquid film/droplet thicknesses and surface deformations, allowing measuring angles of surface inclination in the range of [- 5^∘, 5^∘] . In the present paper, we investigated the final stage of droplet evaporation of non-volatile water and volatile perfectly wetting liquids FC-72 and HFE-7100. Thin liquid film thickness down to 2 m has been measured by using black silicon substrate (b-Si), which has low reflectivity and high absorption of visible light. The substrate is heated in the temperature range from 20 to 50 ^∘ C. The liquid bump occurrence in the periphery of the non-volatile droplet, the thin liquid film breakup, and ring formation are characterized. The droplet fragmentation into picolitre-sized pieces is observed for volatile low surface tension liquids. The specific evaporation rate is confirmed to increase proportionally to the contact line velocity. The adopted schlieren technique is also found to be applicable for observations from above of the bubble dynamics inside a liquid film and for measurements of the receding contact angles.

Рассмотрена проблема выбора типа волоконно-оптической элементной базы для построения канального и физического уровней информационной инфраструктуры машинного зала центра обработки данных (ЦОД) с учетом ее модернизации в процессе текущей эксплуатации. Показана целесообразность выбора показателя экономической эффективности NPV как основного критерия принятия решения. Адекватность предлагаемой модели усилена учетом фактора неопределенности по показателю Гурвица. Представлены аналитические выражения и результаты расчета. The problem of choosing the type of fiber-optic element base for building the channel and physical levels of the information infrastructure of the data center's computer room, taking into account its modernization in the course of day-to-day operation, is considered. The expediency of choosing the NPV economic efficiency indicator as the main criterion for decision-making is shown. The adequacy of the proposed model is enhanced by taking into account the uncertainty factor in the Hurwitz indicator. Analytical expressions and calculation results are presented.

An approach to determining the patch cord length of the central data center crosses with spine-leaf architecture, which is based on the Monte Carlo method is proposed. The possibility of its implementation in Excel spreadsheets is shown. The results of calculating the length distribution when installing the cross in cabinets with a height of 42 and 47U are given. It is established that for the majority of cords the length of 1–1.5 m is sufficient. The need to use 800 mm wide cabinets for the central cross and the possibility of placing it in one cabinet for 126 leaf level switches when building a data center according to the top-of-rack scheme is substantiated.

В статье приведена оценка текущего состояния и перспективы развития симметричных кабелей (LAN-кабелей). Отмечается, что в настоящее время разработана отечественная измерительная система А132 для измерения электрических параметров LAN-кабелей и коаксиальных кабелей.

The changes in the structure and phase composition of a part made from the domestic VT6 titanium alloy powder produced at AO SMK by injection molding of a powder–polymer mixture, which are caused by a change in the sintering conditions of a porous semifinished product, are investigated.

This work is devoted to the study of the rheological behavior of a powder–polymer composition prepared for use in injection molding technology. A review of the models used to describe the rheological behavior of slurries is presented. Viscosity was studied on a capillary rheometer with different capillary diameters using MIM-4140 feedstock with a wax–polyolefin binder as an example. Empirical coefficients of viscosity models are determined. Verification of the calculated values of the viscosity of the studied feedstock and experimental data is presented.

Федеральное государственное бюджетное учреждение наукиИнститут неорганической химии им.А. В. Николаева Сибирского отделения Российской академии наук

The article presents the mathematical description of minerals industry enterprises electrotechnical complexes. The presented development and modification of algorithms and methods for calculating the parameters of electrical complexes structural elements are taking into account the specifics of the technological process. The developed methods of studying the operating modes of electrical complexes of oil and gas production enterprises are planned to be used to identify various promising dynamic modes, which, in turn, will allow determining the optimal operating conditions of electrical complexes regardless of their structure, including in conditions of uncertainty and incomplete information.

Simulation models of power-supply systems with sources based on gas-turbine units with different structures and compositions of components and analysis of their functioning taking into account various technological factors and specifics of the power system are considered. The calculation of the dynamic conditions is represented as a sequential calculation of the static modes at each sampling step. Models of power-supply system components have been developed, including a nonlinear model of a gas-turbine unit and a model of the source of nonlinear distortions. The presented method for calculating the parameters of the models of power-supply system components allows one to model complex modes of power-supply systems powered by autonomous sources. For verification of the calculations, a seminatural model was developed based on the laboratory “synchronous motor–dc motor” setup. The approach proposed makes it possible to improve the accuracy of modeling interrelated processes and to expand the range of the tasks to be solved including modes that are not recorded by instrumental measurements. The results of the scientific and engineering solutions implemented in industrial conditions have good convergence confirmed by seminatural models and instrumental surveys.

A method for calculating the limiting length of the MPTL-channel for Long Ethernet system is proposed. The method is based on assessment of the main part of the Shannon capacity, taking into account its dependence on the specification parameters of the element base used for formation of the channel, as well as dispersion distortions of the signal at lengths twisted pair channel more than 100 m. A ...

The evaporation of water drops with an initial volume of less than 2 mu l on smooth copper substrates with carbon coatings was studied. Cases of evaporation of sessile water droplets into open atmosphere were considered in the substrate temperature range from 24 degrees C to 100 degrees C. The coating of one copper substrate consisted of vertically oriented, multi-walled carbon nanotubes. Another substrate was coated with horizontally oriented, single-walled carbon nanotubes. The morphology of the coatings was analyzed using scanning electron microscopy and atomic force microscopy. For comparison we used one polished copper substrate with the root-mean-square roughness of about 20 nm. With the help of a precise drop shape analysis system, the droplet evaporation dynamics was studied. A quantitative analysis of the data showed that the evaporation rate on the substrate with vertically oriented nanotube coating is up to two times higher than on the uncoated substrate. No appreciable difference was detected in the evaporation dynamics of the droplet between the horizontally oriented carbon nanotube coating and the polished copper substrate within the substrate temperature range studied.

The article considers the method of constructing two-dimensional probability density function of non-Gaussian random processes using one-dimensional probability density function. The method is based on the use of a specially constructed transition probability density function. Kullback-Leibler probability estimation is applied to analyze how close the approximating function approaches the initial function. The property of monotonic approximation of the approximating function to the initial one with the growth of the correlation coefficient in a wide range of variation of the dispersion values is substantiated. A special procedure for constructing the transition function is proposed, which is based on the Gaussian curve and gives a minimum approximation error in a wide range of parameters. Examples of application of the proposed method to the particular case of Laplace distribution, which is often found in real telecommunication and measurement systems, are given. It is shown that in a wide range of variations of the correlation coefficient, the value of the divergence of the initial and approximating functions is quite small. This property allows the proposed method to be widely used in the study of non-Gaussian processes in various broadband radio and cable systems of local and public communication.

Possibilities of application of Fast Ethernet repeaters for extension of the limit length of twisted pair channel of industrial automation systems are considered. A mathematical model of the line with 100 Mb/s performance has been introduced, which allows to perform engineering calculation of the limit length of a single segment and the whole line. It is shown that in the case of Class 1 devices in terms of power consumption in the line, up to three repeaters can be used, one of which is used in the booster mode and must support the PoE+ mode. It has been established that for Class 1 devices, the main means of extending the limit length of the channel is using a twisted pair cable of Category 5e with cores of increased diameter (0.55 mm and more).