This article presents the results of an experimental study of the deep cooling of natural gas combustion products in a condensation heat exchanger of a waste heat exchanger in a boiler house No. 12 at the Federal State Budgetary Educational Institution of Higher Education "National Research Ogarev Mordovia State University". The heat scheme of the boiler house with the flue gas heat exchanger provides the maximum continuous cooling mode. The study identified the factors that have the greatest impact on the efficiency of the heat exchanger-utilizer.With short-term operation of the boiler in the spring and autumn periods, the efficiency is more than 3%.
Keywords: burner, combustion mode optimization, heat utilizer, boiler room thermal circuit, boiler unit, flue gases, condensation, heat exchanger, cogeneration mode, cooled gases
The electrical properties of composites based on La0.7Sr0.3MnO3 (LSMO) synthesized at the percolation threshold have been studied: LSMO / Li4P2O7, LSMO / Sb2O3, LSMO / GeO2. The activation energies of these compounds have been determined. New ceramic materials with silver interlayers between LSMO manganite crystallites have been synthesized. The current-voltage characteristics for the LSMO / GeO2 series are given. The nonlinearity of the characteristics is most pronounced for compositions near the percolation threshold, 85% LSMO / 15GeO2.
Keywords: lanthanum strontium manganite, composite material, ceramics, one-step synthesis, magnetoresistance, percolation threshold, dielectric constant, barrier layer, tunneling, spin polarization
The paper describes the implementation of a fiber-optic single-channel vibration sensor built on the basis of two fiber Bragg gratings, a broadband source, a photodetector and a sound card of a computer used as an ADC
Keywords: vibration, fiber optic sensor, fiber Bragg grating, Fourier transform
For the first time, the decline in the power consumption of filament light-emitting diode lamps of different firms and power after their inclusion in the electric grid to the full stabilization of its values was investigated. These data are necessary for further clarification of the mechanism for the decrease in the light flux of LED lamps and the reduction in their energy efficiency that occur during the initial period of their operation.
Keywords: filament LED lamp, power consumption decline, luminous flux, energy efficiency, the mechanism of recession
The article describes a method for suppressing harmonic current distortion in a power line without direct measurement , to which a nonlinear load is connected, using a device, which not requiring a continuous current spectral analysis. The oscillograms of currents in the connection node of the device for suppressing higher harmonic currents, obtained as a result of simulation modeling of the operation of the power system with a nonlinear load and a Matlab / Simulink filter, are presented. A mathematical description of the proposed principle of suppressing the highest current harmonics is presented.
Keywords: suppression device, harmonic distortion, simulation, power line, impedance, electromagnetic interferencer
The aim of the article is to analyze the existing methods for constructing a model of random errors in micromechanical sensors. A comparison of different methods for determining the parameters of a random process model is presented: autocorrelation, power spectral density analysis, time domain analysis, and Allan variation analysis. This direction is also supplemented by considering the effect of sensor errors on the error of inertial navigation systems. In conclusion, the synthesis of forming filters for various random errors in micromechanical sensors and the results of simulation are given.
Keywords: mems gyroscope; noise analysis; stochastic drift; error modelling
There are represented scheme and design of duplexer for the 300-344 MHz radio station. Simulation of duplexer was implemented in Microwave Office environment. Experimental research was executed on the complex transmission coefficient measuring instrument such as “Obzor-103”. There are shown amplitude-frecuency characteristic of receive and transmission channels. Comparison of the simulations results with natural experiment proving the identical.
Keywords: Filter, duplexer, amplitude-frequency characteristics, receive channel, transmission channel
A novel compact easy-to-manufacture design of 20 dB directional coupler has been proposed for a high power operation within frequency band 4-12 GHz. In order to obtain the broad band frequency response a three-section asymmetric coupled strip-line directional coupler has been chosen. The periodic structures are introduced on the outer edges of coupled strip-lines for the wide-band compensation of the difference between phase velocities of even and odd modes. The successfully fabricated and tested coupler shows high electrical performances. The proposed 20 dB directional coupler provides within frequency band 4-12 GHz the coupling characteristic imbalance 0.5 dB, isolation 35 dB, directivity 15 dB and VSWR<1.35. The allowable input power of directional coupler is up to 100 W. The coupler dimensions are 39x35x26 mm.
Keywords: directional coupler, coupled strip-lines, even and odd modes, periodic structures, phase velocity of modes, lines with side coupling
A study of the directional coupler range 1-4GHz. The description of the construction on a symmetrical strip line with a lateral connection is given. The amplitude-frequency characteristics were simulated using the Microwave Office package. The model of the directional coupler is experimentally investigated, the following results are obtained: the working attenuation does not exceed 1.7 dB, the transient attenuation does not exceed 10 dB.
Keywords: Directional coupler, frequency response, flatness, symmetric stripline
The article presents information about the training program "Use of information technologies in engineering, scientific, administrative and management activities", developed within the framework of the project of the "Engineering open public forum of scientific and technological activities, social and technological entrepreneurship "rozmys", which is carried out using the grant of the President of the Russian Federation for the development of civil society, provided by the presidential grants Fund. The program is intended for a wide range of engineers and specialists of industrial enterprises, scientists, research engineers, University professors, specialists in the field of administrative and management activities. In it, participants are invited to master a number of professional competencies in the field of organizational management using computer modeling. Forms of training are distance video lectures and practical classes. For each topic, an intermediate test is carried out, and their results are put up a final assessment. Participants who have successfully completed the training receive a certificate confirming the passage of 16 hour refresher course on our program.
Keywords: distance education, advanced training, organizational management, computer modeling, computer simulators
Red blood cells (RBC) roll like tractor caterpillars along narrow capillaries. On the erythrocyte surface there are charges that, when moving together with the erythrocyte membrane, create a magnetic field in the vicinity of the RBC. Discrete charges are distributed uniformly on the surface of the RBC, their number can reach several million and the charges move together with the RBC membrane. The surface of the RBC is approximated by a truncated cylinder. Discrete charges are located evenly over the surface of the RBC and move along closed curves that are rectangular trapezoids. A mathematical model has been constructed that allows calculating the intensity of the magnetic field produced by mobile charges located on the RBC membrane. According to the Bio-Savart law, the magnetic field strength can be calculated at some point in space if the coordinates and velocity of the charge are known, the distance from the charge to the point and the angle between the velocity vector and the radius vector connecting the charge and the point. If we assume in the first approximation that the medium is isotropic and magnetic currents are absent, then Maxwell's equations can be written out. These equations can be rewritten in the form of equations in finite differences, solving by numerical methods one can obtain distributions of electric and magnetic field strengths in the vicinity of the RBC. Calculations were carried out for different values of input parameters. In the case when the RBCs move through the capillary network, in which the narrow capillaries are located close to each other, the magnetic fields of the RBCs in different capillaries interact, and, as a result, we obtain a new distribution of the magnetic field strength in the vicinity of the capillary network, which varies with time.
Keywords: mathematical model, algorithm, magnetic field strength, electromagnetic interaction, erythrocyte, narrow capillary
the article attempts to build a causal model of social exclusion from the standpoint of the concept of "life situation". To build such a model by means of cause-and-effect analysis, it is necessary to find a thematically relevant starting point, from which in the future, in the dichotomous sense, observations will be made about the exclusion or inclusion in a particular subsystem of society, which will allow to determine a set of indicators to measure inclusion in each specific situation. Next, it is possible to set the degree of inclusion in the appropriate subsystem.
Keywords: social exclusion, social inclusion, life situation, life chances, causal model of exclusion
The article is devoted to the study of the thyristor regulator of the booster voltage harmonic composition in the mode of longitudinal-transverse regulation. The results of the harmonic analysis of thyristor regulator output voltage , obtained using simulation in the Simulink package, are presented.
Keywords: longitudinal-transverse regulation, thyristor regulator, regulating characteristics, modeling, harmonic analysis, Matlab Simulink
The object of research in the presented work is the influence of photogrammetric and internal refractions on the definition of linear elements of external orientation. At the conclusion of photogrammetry formulas it is supposed that the light beam is a straight line from the object to the center of the projection. In fact a beam of light passing through the atmosphere layers of various density is bent. This bend is called refraction. The determination of the elements of internal and external orientation and corrections to the coordinates of the points of the image by control points is based upon a decision of the spatial photogrammetric back-sight. Compared to the rigorous method a simpler method for solving the spatial photogrammetric back-sight is suggested which validity check performed by the modeling method showed its rather high accuracy.
Keywords: photogrammetry, back-sight, spatial photogrammetric back-sight, refraction, elements of internal and external orientation, control points, modeling method
Research of models of formation of integration projects on the basis of points of growth reveals a number of important aspects related to the stages and management of their implementation. The focus on the formation and support of growth points essentially excludes the use of unary models in the planning and implementation of projects within the framework of national programs. In order to overcome the limitations imposed by this type of project, various integrative mechanisms are proposed. The peculiarity of the considered binary models describing the integration mechanisms is the preservation of the basic cycle of the project points of growth within the national program. However, the introduction of additional contours in the model with growth accelerators, with related or integrated projects, as well as attracted resources can reduce the risks caused by high rates of development and innovation issues. The integration potential of the binary model with the project of the growth point in the basic circuit generates a dynamic competitive advantage, i.e. a sustainable, increasing advantage over time that is not related to the amount of initial funding. This advantage generates a powerful growth cycle that can provide a significant increase in profitability over a long period of time. The integrative nature of growth point projects should be envisaged already at the planning stage of national programmes with appropriate monitoring and funding instruments.
Keywords: Decree of the President of Russia, southern Federal district, points of growth, model, project, program, integration, mechanism
The article provides a solution a schedule generation problem for the timber transportation, a description of the problem is given, and a multi-criteria mathematical model is created. It is indicated that the task in question can be assigned to the class of vehicle routing problems in the general formulation of GVRP related to the job-shop scheduling. A hybrid algorithm for solving the problem based on the decomposition method using the simplex method and the genetic algorithm was developed. Conducted testing showed the effectiveness of the developed method on real data of wood harvesting enterprises. The results of numerical methods testing on real data suggest a reduction of the complexes of forest transport machines downtime, and an increase of transported wood volume during the planning period. The scientific results presented in the article were used in the development of a planning and management system «Opti-Wood» developed by Opti-Soft company.
Keywords: wood harvesting, GVRP, optimization, job shop scheduling, operational logistics, genetic algorithm
The article deals with the problem of optimal control of the train (OKT) from the standpoint of the modern theory of automatic control. This problem is relevant for many years, but to date it has not been completely solved, due to the large number of random factors affecting the nature of the train, as well as the development in recent years of high-speed and high-speed, as well as heavy and long-range traffic. The mathematical model of train movement and formulation of the OKT problem are presented, the classification of known methods of its solution is offered. A simulation model in Matlab/Simulink environment is developed, which allows to study different models and control laws. A metaheuristic algorithm for optimization of train operating modes using a simulation model implemented in the form of a software module in Matlab is proposed. The results of computational experiments confirming the convergence of the algorithm are presented.
Keywords: optimal control, autodriving, mathematical model, simulation model, metaheuristic algorithm
The article presents a hardware genetic algorithm for the synthesis of finite state machines. Testing of the proposed genetic algorithm has shown that its use improves the quality of solving problems of the synthesis of finite automata in combination with a decrease in the time of obtaining a optimal solution (compared to algorithms known in this field). It also describes the hardware and software platform used to build evolutionary hardware. The system was testing by synthesis of finite state machine in the problem of "Smart Ant"
Keywords: evolutionary synthesis, finite state machines, genetic algorithms, evolutionary algorithms, evolutionary electronics
The application of the parameters of the modes of signal allocated using the extremal filtering algorithm is considered. The use and disadvantages of amplitude detectors are described. Use of attenuation are described and shows how to reduce the effect of ""overshoots"". It is proposed to use a combined sign for a more contrast extracting of detection areas. A method for reducing the labor intensity is presented, which consists in applying filtering directly to a number of extrema, without calculating the smoothed components.A method was chosen that allows the signal analysis algorithm to be adapted to work in real time.
Keywords: Security system, diagnostic signs, extreme filtering, mods, real time
This article reveals the scientific and theoretical approaches to the study of social issues in the language context. The authors attempt to present a two-dimensional model of giving the meaning to the modern verbal space. This model offers insights into the process of the formation of social scenarios that are fixed in the language space. In addition, the model developed by the authors provides a researcher with a complete picture of the dynamics of social processes in society, represented by addressing the phenomenon of language as a universal socio-cultural code
Keywords: semiotic model, verbal space, social scenario, discourse, language, social space, socio-cultural code, social phenomenon, sign system
The authors carried out in-situ studies of the distribution of the breakdown voltage values of the F8CV engine of the Daewoo Matiz Diesel engine idling at a minimum engine speed (650 rpm) and with an increased crankshaft speed (2840 rpm). A histogram of the distribution of the values of the breakdown voltage in the interelectrode gap of the spark plug is obtained for these operating modes of the internal combustion engine. It was revealed that at a minimum engine speed of the ICE crankshaft, the distribution of the cyclic values of the breakdown voltages obeys the normal distribution law for a spread of 6-15 kV. At higher speeds, the distribution of the cyclic values of the breakdown voltages differs from the normal distribution law. With an increase in the speed of the crankshaft, all values of the breakdown voltage fall by 3-4 kV. This can be explained by homogenization of the mixture and an improvement in the conditions for breakdown of the spark plug interelectrode gap.
Keywords: ignition system, spark discharge, internal combustion engine, spark plugs, breakdown voltage, histogram
The selective method of calculation because of the profitability is successfully applied several centuries. However when calculating non-failure operation in case of fatigue failures (often sudden) when there is a considerable sedate communication of m=10-15 for the supermulti-cycle field of loading between durability (hardness, an endurance limit) and the operating tension, decrease in the minimum resource of details will make 10-100 and more times. It turns out because of an unaccounted main part of population. In our example of 104-50=9950 pieces of such details, i.e. their potential refusals. Therefore for this case a selective method – the intermediate stage of calculations.
Keywords: selection, fatigue resource, population of final volume, sedate communication
a method for calculation of electro-hydraulic raspylivatelja liquids. Theoretical dependences of the median diameter of aerosol drops on the fluid flow rate at different number of generator nozzle holes, on its main design parameters are presented.
Keywords: aerosol, dispersion, drop, generator, electrohydraulic atomizer
We consider the model of resource allocation for ergodic and semi-ergodic resource networks with valve reachability. Approach for modeling the process of resource reallocation in network with valve reachability is proposed. This approach bases on using of the auxiliary network. Methods for finding the threshold value and the limit state for an arbitrary total resource value in a resource network with valve reachability are developed.
Keywords: resource networks, flows in networks, flow distribution, nonstandard reachability, limit state, threshold
Efficiency, quality and safety of construction are formed by the levels of management and integration relations between the enterprises of the industry and Federal services. Multidirectional construction business contributes to the formation of various types of inter-industry relations. Currently, intra-industry relations are dominant, which are typical for cluster formations in market conditions of development under the existing uncertainty. Effective management of supply and demand affects the stable profit of the construction industry.
Keywords: construction, management, territorial features, industry features, production, competition, integration associations