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
This article discusses various configurations of dielectric inhomogeneous waveguides in the microwave range, discusses the results of computer electrodynamic modeling of the proposed configurations of structures with periodic inhomogeneities. During the simulation, the geometric and electrophysical parameters of the periodic structure were varied in order to identify their influence on the characteristics of the proposed sensor to determine the properties of liquid dielectric media.
Keywords: dielectric waveguide, Bragg reflection, dielectric constant, reflection coefficient
The article focuses on radiowave propagation in complex conditions combining rough terrain with woodland or urban areas. The estimation of influence of all these factors on signal attenuation may be challenging. Consequently there are no propagation models for such environment for distances up to several kilometers. However by approximating the experimental data on radio wave attenuation it is possible to develop empirical propagation models for specific cases. The authors carried out a series of experiments to measure the level of radio signal at a given distance from the source. Based on the experimental results a hybrid model for rough terrain, wooded and urban areas for ground communications systems was developed.
Keywords: radiowave propagation, UHF, experimental study, rough terrain, urban area, wooded area, empirical model, radiowave attenuation, path loss, ground mobile communication
The statistical characteristics and results of the FIPS 140-2 tests of a new class of pseudo-random signal generators based on modified Lorentz, Chua and Dmitriev-Kislov systems over the finite Galois field are considered. The estimates of the sidelobe levels of the correlation functions of the signals, as well as histograms of the probability distributions of the generated numbers, are obtained. Evaluations of compliance with the requirements of the FIPS 140-2 test of binary sequences generated on the basis of systems under variation of their parameters are obtained. The results of the work can be used in the construction of communication systems with broadband signals, simulation and cryptography.
Keywords: dynamic chaos, radioelectronic dynamic systems, statistical properties
A theoretical calculation of the transmission coefficient of the microwave converter on a resonant tunneling diode, where the same diode is used as a mixer and amplifier of microwave oscillations, is carried out. In this case, as shown by calculations, the transmission coefficient increases due to the use of regeneration, and also because the non-linearity of the current-voltage characteristic of a resonant tunneling diode is much larger than that of conventional microwave diodes with a Schottky barrier.
Keywords: transfer coefficient, regeneration, resonant tunnel diode (RTD), volt-ampere characteristic (VAC), input amplifier, equivalent mixer, intermediate frequency transfer coefficient, input amplifier transfer coefficient, dual-barrier heterostructure
The article contains information about the formats, types, advantages of banner advertising, made analysis of errors that allow developers and customers, developed a General principle of successful visualization of banner advertising for the tourism sector.
Keywords: banner advertising, banner, tourism, offer, Internet, advertising, efficiency, layout, layout, rule of thirds
The efficiency of optical radiation input of semiconductor lasers of various types into an integrated optical ion-exchange buried waveguide in glass was calculated using optical circuits based on spherical, hemi-cylindrical and hemispherical lenses. Calculations were made by using the method of ray tracing. The single-mode waveguide, used in calculations, is the glass (type K-8) waveguide, made by ion exchange with subsequent burying. The results of the calculations indicate a low efficiency of optical radiation input when using single lenses. The use of a pair of microlenses (collimating and focusing) makes it possible to significantly increase the efficiency of optical coupling, which is 79% for a VCSEL laser. Efficiency of input is limited by a sufficient low aperture of the glass waveguide itself - 0.12. For more precise simulations the race tracing method with wave correction was used. The wavelength of optical radiation for calculations is 1.3 micrometer. The use of a single spherical and cylindrical lens has the advantage for it’s simplicity, but will lead to a serious loss of power in the optical system and, correspondingly, an increase of signal attenuation. This is partly due to reason that when using a single cylindrical or spherical lenses, according to the geometry of the calculations, the optical radiation will not be focused at one point, and essential aberrations take place. Efficiency of coupling with the help of two lenses is limited at first, by numerical apertures mismatch and, at second, partial energy transfer to the rings of Airy disk. The ion-exchange waveguide is suitable for coupling with VCSEL lasers for application in planar waveguide concentrators, etc.
Keywords: integrated optics, optical waveguides, ion exchange in glass, VCSEL laser, ray tracing method, ZEMAX
Using the methods of thermo-programmed reduction (TPV) and thermo-programmed hydrogen desorption (TPD H2), physico-chemical studies of Co-MxOy / SiO2 catalysts obtained by various methods of introducing a promoter additive were carried out. The effect of the introduction method and the nature of the promoting oxide additive on the properties of the active component of the Fischer-Tropsch synthesis catalysts was studied.
Keywords: Fischer-Tropsch synthesis, catalyst, active component, silicate carrier, Al2O3 and ZrO2 promoters, TPV and TPD H2 methods, crystallite size, degree of reduction, dispersity
The article presents the author's theoretical and methodological construct of the study of socio-political behavior of the social actor. The developed construct is based on the concept of habitus introduced into the scientific discourse by Pierre Bourdieu. The socio-political habitus in this article is understood as interiorized patterns of perception, interpretation, evaluation and action in the socio-political space, which are constantly being refined and completed under the influence of everyday social practices. Denoted epistemological problem of combining the contradictory nature of the conduct and integrity of the habitus. As a solution to the problem, such a property of habitus as hierarchy is considered. It is assumed that in the deep structures of habitus there are integral models of social dynamics, which are reproduced in socio-political relations by spontaneous coordination of social practices of many social actors. However, each social actor represents a single element of the complex model. Such social dynamic models in this article are denoted by the term "myth". On the basis of the presented theoretical model, the solution of applied problems in the management of socio-political behavior is proposed. At the same time, the authors proceed from the fact that mythological complexes in the structure of the habitus can not be eradicated or replaced, but can be overbuilt.
Keywords: political relations, model, myth, habitus, management, regulation mechanism, calibration
Physical and chemical properties of cobalt catalysts for Fischer-Tropsch synthesis are investigated. The influence of copper and zirconium oxides on the specific surface area, cobalt concentration, pore volume and size, the degree of reduction of the catalyst Co-Al2O3/SiO2 was studied.
Keywords: Fischer-Tropsch synthesis, carbonaceous resources, catalyst, active component, silicate carrier, CuO and ZrO2 promoters, elemental analysis, recovery rate, BET method, specific surface area
The study of physical and chemical properties of cobalt catalysts in the synthesis of hydrocarbons by the Fischer-Tropsch method is carried out. The effect of additives promoters NiO, Fe2O3, MnO2, on the specific surface area, pore volume, size of cobalt crystallites, the degree of catalyst reduction is considered
Keywords: Fischer-Tropsch synthesis, synthetic hydrocarbons, catalyst, promoter, carrier, specific surface area, porous structure, catalytic activity, dispersion, cobalt crystallites
The article reviews considers the current state of automated process control systems. The main disadvantages of these systems are identified: the lack of full integration of process control systems into a single enterprise system, the lack of a single system of monitoring and diagnostics of equipment, local data storage. The principles of development of automation of the chemical industry in the conditions of digital production, such as end-to-end modeling, implementation of a unified data collection system based on the technology of industrial Internet of things, the introduction of cloud technologies to store the accumulated database and knowledge. This strategy of automation development allows to increase the competitiveness of the chemical industry.
Keywords: production automation, digital production, end-to-end modeling, industrial Internet of things, production management integration.
The article deals with the construction and definition of the stress-strain state of the design scheme of a lattice tower-like structure in the form of a mesh hyperbolic paraboloid. The dependence of the wind load distribution on the characteristics of the form is established, a sectional calculation method for such structures is given.
Keywords: Hyperbolic paraboloid, finite element method, aerodynamic loads, lattice towers
To ensure the stability of the galvanic deposition process and the high quality of the precipitate obtained, it is necessary to know the dependence of all processes on technological factors and modes. The degree of influence of technological factors on the behavior of machine parts made of gray iron, etching and deposition of zinc electroplating is not the same, so there is a need for electrochemical studies in the laboratory. The methodology of such studies has a General orientation and particular conditions in each case. The article describes in detail the method of electrochemical studies of gray cast iron in the sulfuric acid electrolyte of galvanizing during the restoration of machine parts by galvanic deposition of zinc coating. The basic conditions necessary for obtaining reliable comprehensive results that will determine the optimal conditions for galvanizing machine parts made of gray cast iron are considered.
Keywords: technological factor, electrochemical studies, polarization curves, electrochemical cell, electrode, potentiostat
The article discusses the dynamic characteristics of mineral wool materials (dynamic modulus of elasticity and stiffness, reduced dynamic stiffness) and the effect on them of porosity and relative deformation of the material. The main objective of the study is to determine the value of the dynamic modulus of elasticity, taking into account its change with time under the action of a long-term static load for calculating the impact noise insulation.
Keywords: mineral wool material, dynamic modulus of elasticity, strength of parts of a structure, sound insulation, ultimate states, construction