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  • Investigation of partial backup options in the design of fault-tolerant logic blocks in FPGAs

    In this article, we propose methods for designing fault-tolerant structures for Field Programmable Gate Arrays (FPGAs) by forming an internal structure of macro cells (LUTs), with the possibility of correcting single reversible faults in the circuit’s gates. To improve fault tolerance, the failure tolerance of a typical macro cell was assessed, the most vulnerable areas were identified and the most vulnerable parts of the macrocell were protected by means of triple modular redundancy methods. Depending on the expansion of the protected area, various versions of the built-in redundancy were obtained, and various options for minimizing the built-in redundancy were proposed. Experimental work was carried out to form fault-tolerant ISCAS'85 combinational circuit designs in the basis of fault-tolerant FPGAs.

    Keywords: combinational circuit, FPGA, field-programmable gate array, LUT, logic synthesis, increase fault tolerant, computer-aided design (CAD), fault injection, single event transient

  • Numerical study of the heat sink with a change in the aggregate state of the working substance

    In the article, a numerical study of the heat sink with a change in the aggregate state of the oil is carried out. Simulation was carried out in Ansys Fluent CAD for two modes, static - with constant heating of the oil at 340K and dynamic, at which the heating temperature varied with time from 340K to 270K. Heat transfer in the event of a change in the aggregate state of a substance is widely used in cases where it is necessary to achieve the maximum efficiency of heat exchange. In this case, the energy is expended on the phase transition of the substance, for example, to evaporation from the liquid phase. The advantage of the heat-sink design described in this work is a rather high rate of heat transfer, greater resistance to various influences, including mechanical ones, which is primarily ensured by the simplicity of construction, eliminating the drawbacks of classical designs, which are cumbersome (the presence of an external cooling circuit ) and the limited rate of heat transfer.

    Keywords: heat dissipation, numerical methods, aggregate state, computational experiment, heat exchange efficiency

  • Recycling of polyethylene terephthalate using chelate erbium complex

    This article presents the results of studies on the effect of the erbium chelate complex on the processing of secondary raw materials from polyethylene terephthalate (PET).

    Keywords: polyethylene terephthalate, recycling, extrusion, polyisobutylene, chelate complex of erbium.

  • Investigation of the efficiency of the pin heat sink by numerical methods

    In the article, the authors carried out a computer experiment in Ansys Fluent CAD to study the efficiency of a heat sink surface in terms of reducing the temperature of a heat-loaded source. Providing optimal thermal conditions for electronic products is one of the most important problems in the design of radio electronic equipment. Increasing the temperature of electronic products significantly reduces the reliability of their work. The work is devoted to numerical modeling of the heat sink surface efficiency of a pin radiator with an internal heat source. A conclusion is drawn about the ineffectiveness of performing a heat sink pin surface, not the entire surface is equally effective.

    Keywords: thermal mode of equipment, pin heat sink, numerical methods, aerodynamic flow

  • Investigation of the physico-chemical properties of promoted catalysts based on Co-Al2O3 / SiO2

    The physical and chemical properties of cobalt catalysts for the Fischer-Tropsch synthesis prepared by the method of impregnating a silicate carrier have been studied. The influence of oxide promoters on the specific surface, volume and pore sizes, the degree of reduction of metallic cobalt on the surface of Co-Al2O3 / SiO2 catalyst has been studied.

    Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, cobalt, promoter, carrier, specific surface, porous structure, catalytic activity, degree of reduction

  • A method for improving the convergence of a single-center decomposition of a molecular orbital

    Investigation of the interaction of electromagnetic radiation with molecular systems gives most of the information about their structure and properties. Interpretation of experimental data is directly determined by the knowledge of the structure of energy levels and its change in the transition of these systems to an excited state. A key task of the methods for calculating the molecular orbitals of excited states is to accurately describe the emerging vacancies of the molecular core, leading to radial relaxation of the electron density. A method is proposed for an exact description of the electron density of a molecular system near its nuclei, which provides solutions to the problem of slow convergence of molecular orbitals in a single-center representation. The implementation of the computational procedure is examined using the example of a diatomic hydrogen fluoride molecule. The energy characteristics of the ground and ionized states of the molecule are estimated

    Keywords: single-center method, molecular orbital, excited state, ionized state, deep shell

  • Thermophysical basis of the engineering calculation of the package thickness of the sleeping bag

    In this paper, we propose a technique for calculation of the thickness. This technique is allowed to determine the thickness of a sleeping bag based on data on the equivalent coefficient of thermal conductivity of a sleeping bag package and data of heat production of person during the sleep. The values and trends in the variation of the relative discrepancy between the calculated and experimental thickness of the sleeping bags as a function of temperature are explained by the possible differences in the data on the thermal conductivity of the down, and by the necessity to introduce thermal insulation coefficients for individual parts of the body.

    Keywords: Key words: sleeping bag thickness, down, thermal conductivity, thermal insulation

  • Electron temperature in the sporadic E layer of the ionosphere of the Earth

    The necessity of studying the thermal balance of electrons in the ionospheric sporadic E layer to clarify the conditions of its formation in the framework of the theory of the wind shear. The method of calculation of the altitude profile of electron temperature in the sporadic E layer of the ionosphere. Reported satisfactory agreement between the calculated profile of the temperature of the eiectrons and its experimental profile.

    Keywords: ionosphere electron, temperature, sporadic layer, heat balance, the heating rate, wind shear, altitude profile of the temperature probe measurements

  • Effect of Al2O3 carrier modification on the properties of cobalt Fischer-Tropsch synthesis catalysts

    The parameters of the porous structure and the outer surface of cobalt catalysts for the Fischer-Tropsch synthesis prepared by the water-impregnation method were studied. The effect of the polymorphous modification of the support on the physico-chemical properties of the Co / Al2O3 catalyst was studied.

    Keywords: Fischer-Tropsch synthesis, synthetic motor fuel, catalyst, carrier, promoter, polymorphic Al2O3 modifications, elemental analysis, specific surface, porous structure

  • Development of metal-ceramic composite material for the friction unit of the absorbing apparatus of the railway car

    The absorbing apparatus serves to extinguish the impact when the wagons cohere and move. Most of the energy, about 80%, in this system is absorbed by a friction unit consisting of a friction wedge and a fixed plate. Absorption of energy in this system occurs due to the work of frictional forces arising during longitudinal motion of the pressure wedge with respect to the friction plate. Due to the large shock-frictional loads, intensive wear and destruction of the cermet cake occurs, which adversely affects the energy capacity of the absorbing apparatus. To eliminate these shortcomings, studies were conducted to create a new material. After numerous experiments, a composition was obtained with the optimum content of components, which maximally satisfies the working conditions of the friction unit and the requirements imposed on these devices.

    Keywords: absorbing apparatus, friction unit, cermet, wear resistance, friction plate, powder material, sintering technology

  • Analysis of theoretical cycles of piston engines

    The article deals with the analysis of theoretical cycles of internal combustion engines. Presents Otto cycle, Diesel and Sabate-Trinkler. The theoretical cycle is a closed cycle occurring in the cylinders of the piston engine with its inherent features and assumptions. Each cycle is characterized by two main indicators, such as heat use and efficiency. In this case, the thermal utilization is determined by the thermal efficiency. The estimation of influence of thermodynamic factors on change of thermal efficiency for reception of the best efficiency and the maximum specific work of cycles is resulted. The thermal efficiency of the mixed cycle is obtained. The conclusions of the influence of the compression ratio on the thermal efficiency are presented. A comparison' of different theoretical cycles from the point of view of their cost-effectiveness and efficiency under the same conditions.

    Keywords: internal combustion engine, ideal cycle, thermal efficiency, thermal processes

  • Optimization of the boiler house thermal scheme with the utilization of flue gas heat

    The article gives an overview of the ways to utilize the heat of the boiler exhaust gases. In conditions of actualization (both technical and economic expediency) of application of technologies for fuel economy and environmental protection, the use of aggregates based on the internal combustion engine and microturbines with the utilization of the heat of the cooling system and exhaust gases has found application. Deep cooling of combustion products of natural gas both in boilers (condensing boilers) and in special condensing heat exchangers (utilizers) makes it possible not only to organize the full utilization of the physical heat of the flue gases (the lowest heat of combustion of the fuel), but also to select the latent heat of condensation Water vapor. The coefficient of efficiency of the boiler-aggregate will be increased in this mode by 8-12%, provided that the boiler operates in the optimal mode. Cooling of combustion products also reduces the content of nitrogen oxides in flue gases, incl. With the use of heat pump plants. The efficiency of the implementation of projects for the installation of condensing heat exchangers depends to a large extent on the number of hours of operation at maximum capacity in the mode of deep utilization. In this connection, we propose a variant of optimization of the boiler room thermal scheme with the heat recovery of the flue gases.

    Keywords: Heat recovery boiler, boiler house thermal scheme, optimization, boiler, flue gases, heat generating unit

  • Development of the device for detecting the blooded vessels

    An experimental device designed for the detection of peripheral veins during the injection and infusion was developed on the basis of recording the difference in the intensity of the optical signal reflected from the vessels and surrounding tissues. The device allows to perform the detection of the locations of vessels, to determine their projection, to confidently distinguish veins and arteries. The effectiveness of the application is shown in tests on healthy people and patients with diabetic angiopathy. The device is very compact, has a simple design and low cost.

    Keywords: infrared light, optical pair, photodiode, LED, introscopy, vascular detection, complicated intravenous access, peripheral vein, photoplethysmography, angiopathy

  • Research of the filtering algorithm in an acoustic glass break detector based on the STM32F4XX microcontroller

    In this paper, the effectiveness of implementing DSP algorithms necessary to realize the fact of glass breaking in a controlled room is considered. In the course of the research, existing schemes for constructing glassbreak detectors used in existing fire and security alarm systems are analyzed. The possibility of constructing digital filtering algorithms on microcontrollers STM32F4XX of medium degree of integration is investigated. Studies have shown the fundamental possibility of implementing DSP algorithms necessary to detect the fact of glass breaking on STM32F4XX microcontrollers in real time.

    Keywords: digital signal processing, burglar alarm system, glass break detector, digital filter, finite impulse response, microcontroller performance.

  • Opto-electronic device of forming a flat multi-color light raster large size

    Flat multicolor light rasters larger sizes can be used for orientation of the aircraft relative to the runway. In the case of the use of such light vehicles in the route and glide-path system (KGF) landing aircraft to increased demands. It should be reliable, efficient, weatherproof and safe. The safety of the pilot is of importance both from the point of view of security applications of KGF as avionics, and increasing psychological and emotional stress, and richness of information flows. As well as the reliability of the system is a guarantee of minimization of emergency situations, leading to the work of the pilot in a stressful condition when a person has reduced functional performance (reduced attention, drops his concentration), speed of decision making and actions can be reduced and, accordingly, affect the results of its activities. Despite the high level of automation of process of landing of an aircraft on the runway, visual perception a pilot environment remains a key in taking a final decision. A particularly acute problem when landing on small platforms, including on the platforms of shipborne. The sooner the pilot will visually assess the environment, the more time it will have for decision-making, especially in conditions of poor visibility and the presence of radio interference.

    Keywords: the light raster, semiconductor lasers, galvanoscanner, line scan, frame scan, sector, raster geometry raster, route and glide-path system

  • Analysis of the categorical diagram of the adaptation contour of the bioinstrumental information-measuring system

    The article analyzes the adaptation contour, which is an integral level of management of the body's hematopoietic system, aimed at optimal maintenance of the body's metabolism as a whole. It is indicated that for complex measurement problems it is advisable to use the principles of constructing measuring systems, formulated in terms of system functions using the fractal-categorical approach. It is concluded that the functorial and category maps make the analysis of the hematopoiesis process more complete and visual, and the possibility of further decomposition allows the researcher to carry out more detailed research, visually displays the processes of adaptation of the organism under external influences and naturally contributes to the construction of automated measuring systems for which the adaptive The contour is a model of the bioconverter of information on the processes of hematopoiesis included in composition of bioinstrumental measuring system

    Keywords: structural and analytical method, information-measuring system, information flows, hematopoietic system, category diagram, functors, adaptation contour, bioinstrumental information-measuring system, control signal, measurements

  • Development of a method for determining the magnitude of light flow decrease of filament lamps based on the state standard of the Russian GOST R 54350-2015

    To significantly increase the accuracy of measurement and the reproducibility of the results, a method has been developed for determining the decrease in illumination of filamentary LED lamps. The necessity and possibility of realization of the first reading of illumination in one second is grounded.

    Keywords: filament lamp, illumination recession, method, error, criterial value, rate of decline

  • Research methods of ice characteristics of water bodies

    The paper is devoted to an overview of the methods of ice characteristics of water bodies studies (such as an indicator of the ice cover, the timing and duration of the phases of ice regime). The advantages of the use of multispectral satellite imagery to assess ice conditions of water bodies over the other methods are listed. The difficulties of obtaining data on a particular water body under study are shown. These difficulties appear because of the identification problems of the water body when interpreting satellite images (maps).

    Keywords: ice characteristics, water, earth remote sensing, interpretation, multispectral imagery

  • Super resolution in digital holography

    The article considers a method of increasing the resolution of images in holographic systems based on subpixel shift algorithms. Methods of solving systems of equations of large dimension by reducing to block form are considered. The simplest solution is obtained when a set of matrices with an increased resolution is formed from a set of matrices with a shift in one direction, and then the resultant matrix is formed from the resulting set.

    Keywords: super resolution, subpixel shift, holography, solution of systems of equations, holographic interferometry, aperture

  • Features of the formation of optoacoustic waves in biological tissues

    In work methods of generation of an optoacoustic signal for studying biological tissues are considered, the advantages of the method are shown. Ultrasound studies of biotissues are based on the detection of mechanical properties in biological tissues, ultrasonic methods do not allow to establish the level of oxygen saturation or hemoglobin concentration. Optoacoustic methods can allow to determine the properties of tissues and give images with high contrast at high ultrasound resolution in relatively large volumes of biological tissues.

    Keywords: optoacoustics, optoacoustic waves, biofluids, spherical sources, absorption, oxygen saturation, near field, far field

  • Measurement of short-term instability of the frequency of superstable quasi-hormonic signals

    The work is devoted to the detection of instability in the frequency of generators, which provide synchronization of digital communication networks. An algorithm for detecting short-term instability of the frequency of superstable quasi-harmonic oscillations

    Keywords: synchronization, instability, frequency, Alan variation, multiplicative-transformative criterion, harmonics

  • Comparative analysis of recursive methods of frequency estimation

    The paper presents results of a study of operational recursive methods for quasiharmonic signals frequency estimating over a short observation interval. Such methods should be used, for example, for adaptive control of directional pattern of hydroacoustic antennas in inhomogeneous medium. We proposed recursive expressions for realizations of four methods of frequency estimation within the limits of sliding observation interval. The expressions require a minimum number of mathematical operations, which does not depend on the observation interval length. We carried out comparative analysis of the speed, accuracy, and stability of the methods. The stability of the methods was analyzed based on results of model signals processing with constant amplitude, frequency, and initial phase in presence of additive white normal noise. The accuracy was investigated by the processing results of signals with slow varying amplitude and phase. The paper also presents the results of processing of long sequences of modulated signals with additive noise within a sliding window with predetermined duration. The obtained results make it possible to select from among the four methods the optimal one according to one or more criteria.

    Keywords: communication channel, directional pattern, frequency estimation, recursive method, accuracy of method, stability of method, sliding interval

  • Two low-noise amplifiers

    An experimental investigation of two low-noise amplifiers is carried out. The first amplifier contains one cascade on the HMC374 chip, the second LNA contains two cascades on the same chip. Amplitude and amplitude-frequency characteristics of both amplifiers are obtained, a comparison with the passport characteristics is made. The amplifiers correspond to the passport data for all parameters, except saturation power at the upper boundary frequency.

    Keywords: Low-noise amplifier, amplitude-frequency response, amplitude characteristic, saturation power

  • Monitoring of Toxic Air Contaminants in Southern Federal District

    The article presents a comprehensive analysis of emission indicators from stationary sources and emissions from motor vehicles in the Rostov region and the city of Rostov-on-Don, as well as a comparative analysis for the two regions of the Southern Federal District. The forecast of the ecological situation is made and the adequacy of the proposed mathematical model is checked.

    Keywords: emissions of pollutants, toxicity, exhaust gases, stationary sources, auto transport, internal combustion engine

  • Model for optimizing the tuning coefficients of a firmware measuring channel

    When developing large information-measuring and control systems, special attention must be paid to the interaction of various blocks of the system with each other. For example, the structure of a software-hardware measuring channel consists of four consecutively connected elements: primary converter; analog-to-digital converter; software dynamic converter; digital to analog converter. To find the parameters of the measurement channel error, mathematical models were constructed for each of the blocks. Simulation modeling of the measuring channel was carried out. As the input signal, the first-order aperiodic link model is taken. To generate the interference signal, a random number generator with a noise level of 0.5 is used. The error for the measuring channel is found. The suggested mathematical model allows to find the tuning coefficients of the software of the measuring channel, which ensure the minimum information loss in the software-hardware measuring channel. The resulting model can be used in automatic control systems for the current identification of regulator settings.

    Keywords: model of measuring channel, model of primary converter, adjustment of coefficients, error of measuring channel