Electrodynamic Parameters Research Articles

Mathematical formalism of Joule-Thomson process for ADS-RN black hole coupled with non-linear electrodynamics field

We analyze the thermodynamic potentials and Joule-Thomson adiabatic expansion of a nonlinear electrodynamics charged AdS black hole. The negative cosmological constant is designated as thermodynamic pressure, while the geometrical mass is regarded as the enthalpy. In this study, we demonstrate the analogy between thermodynamic phase transitions in our considered black hole and Reissner-Nordstrom black hole systems, as well as discuss the influence of coupling parameters. The study confirmed the validity of the first law of black hole thermodynamics and the Smarr relation. We have established the Joule-Thomson thermodynamic coefficient and inversion temperature to conduct an analysis of Joule-Thomson adiabatic expansion. Also, the impact of charge parameters and nonlinear electrodynamic parameters on inversion curves have been investigated in detail. The isenthalpic and inversion curves are depicted to determine the cooling and heating regions, explicitly.

Conformal cylindrical microstrip loop radiator input impedance calculation

Problem statement. Antennas that fully or partially repeat the shape of the object on which they are placed are called conformal. The main areas of application of conformal antennas are aviation, rocketry, and vehicles. Despite the presence of a large number of publications devoted to conformal antennas in our country and abroad, issues related to the formation of the radiation characteristics of conformal microstrip antennas, as well as the influence of the overall dimensions and geometry of the emitter on the radiation characteristics, have still not been sufficiently studied. Goal. The purpose of this work was to obtain an approximate formula for calculating the input impedance of a conformal cylindrical microstrip loop radiator. Results. In this article, an integral equation is obtained for the unknown current density distribution function on the surface of a conformal cylindrical microstrip loop radiator; as a result of its solution, an approximate formula for this function is obtained. An approximate formula for calculating the input impedance is obtained. The dependences of the input impedance of a conformal cylindrical microstrip loop radiator on its length normalized to the wavelength are calculated. Practical significance. The proposed method for calculating the input impedance of a conformal cylindrical microstrip loop radiator makes it possible to effectively calculate and study the dependence of the input impedance on the geometric dimensions of the emitter, as well as the dimensions and electrodynamic parameters of the substrate. This technique can be generalized to emitters located on substrates made of other materials, for example, chiral metamaterials.

Detection of low-contrast objects by electrical prospecting methods

Many geological problems cannot be solved by electrical prospecting methods. Often the reason for this is a slight difference in the electrical resistivity of target objects from that of the host medium. At the same time, the use of the transverse magnetic (TM) type field makes it possible to identify low-contrast objects and delineate their boundaries with high accuracy. TM-type prospecting is more efficient since its signal is much more strongly affected by changes in resistivity and other electrodynamic parameters. The article examines one of the difficult cases – a search for kimberlite pipes in Yakutia. Such objects differ very little from the host medium in terms of the horizontal resistivity. Exploration works to search for kimberlite pipes in Yakutia, carried out by conventional electrical prospecting methods, have many problems. The article considers the results of successful TM-type prospecting field surveys where kimberlite pipes stood out very prominently. Also presented are the results of modeling an even more complex situation in which the pipes are located at depths of over 140 m and overlain by traps; there are many objects in the area that create additional anomalies.

Meander Structure Analysis Techniques Using Artificial Neural Networks

Typically, analyses of meander structures (MSs) for transfer characteristics are conducted using specialized commercial software based on numerical methods. However, these methods can be time-consuming, particularly when a researcher is seeking to perform a preliminary study of the designed structures. This study aims to explore the application of neural networks in the design and analysis of meander structures. Three different feedforward neural network (FFNN), time delay neural network (TDNN), and convolutional neural network (CNN) techniques were investigated for the analysis and design of the meander structures in this article. The geometric dimensions or top-view images of 369 different meander structures were used for training an FFNN, TDNN, and CNN. The investigated networks were designed to predict such electrodynamic parameters as the delay time (td), reflection coefficient (S11), and transmission coefficient (S21) in the 0–10 GHz frequency band. A sufficiently low mean absolute error (MAE) was achieved with all three methods for the analysis of MSs. Using an FFNN, the characteristic td was predicted with a 3.3 ps average MAE. The characteristic S21 was predicted with a 0.64 dB average MAE, and S11 was predicted with a 2.47 dB average MAE. The TDNN allowed the average MAEs to be reduced to 0.9 ps, 0.11 dB, and 1.63 dB, respectively. Using a CNN, the average MAEs were 27.5 ps, 0.44 dB, and 1.36 dB, respectively. The use of neural networks has allowed accelerating the analysis procedure from approximately 120 min on average to less than 5 min.

Electrodynamic properties of a rectangular waveguide with a dielectric plate located in the center of its wide wall

A rectangular waveguide with a dielectric plate located in the E-plane is the basic element of devices for microwave heat treatment of sheet materials. In this regard, it is relevant to study the processes of propagation and transformation of electromagnetic waves in such a system. The purpose of the work is to study the influence of the transformation of the electromagnetic field in the air medium of a rectangular waveguide in the zone of propagation of the slow wave H10 on the distribution of electric field energy in the dominant wavelength range and determining the wavelength, at which its maximum value is reached. The range properties of the intrinsic electrodynamic parameters and the field structure of a rectangular waveguide with a dielectric plate located in the E-plane in the middle of its wide wall have been studied. The wavelength at which the maximum energy level of the electric field in the dielectric plate is achieved is determined. The results obtained can be used in the design of microwave heating devices for dielectric materials.

Determination of Electromagnetic Parameters of Liquid Substances in the Microwave Range

The experimental researches of the electrodynamic properties of liquids in the microwave range is described in this work. The calculation formulas within the framework of a single-wave model and the results of trial experiments are presented. Currently, the study of the use of electromagnetic waves in the microwave range (from 0.3 GHz to 30 GHz – UHF (ultra-high frequencies) and SHF (super-high frequencies)) for heating various substances with suitable electrodynamic properties is continuing. Liquid substances are of particular interest in this field. Microwave radiation treatment can be used to solve the problems of disinfection of water, milk, and so on. Microwave heating can be used in the oil industry. An experimental measuring device was assembled to determine the electrodynamic properties of liquid substances. To measure the electrodynamic parameters of substances, a hollow segment of a coaxial line was constructed, which has a disassembly structure and can be completely filled with the test substance before measurements. The dimensions of the coaxial segment are chosen so that, in the absence of filling, its characteristic resistance (impedance) would be 50 ohms, which corresponds to the characteristic resistance (impedance) of the connecting segments of the coaxial lines, and at the same time higher types of waves would be absent in the transmission line. After calibration the measuring object was connected to the system. The frequency characteristics of the VSWR (voltage standing wave ratio) and attenuation were measured using a measuring system. In the absence of filling, the segment is coordinated with the cables of the measuring system, therefore, the reflected wave will be practical ly absent, and the signal attenuation will be determined by losses in the conductors and contact connections of the segment. When filling the line segment with the liquid substance under testing, both the VSWR and the attenuation will change. From this information, it is possible to determine the electrodynamic characteristics of the filling: the tangent of the dielectric loss angle and the complex relative permittivity. To obtain quantitative characteristics, it is convenient to use the D-matrix Keywords: microwave heating, liquid dielectric media, reflection factor, loss coefficient, microwave range, method of D-matrixes method. A scheme of the measuring installation, devices and their connections for experimental research is presented. In the range from 2 GHz to 18 GHz, experimental studies of two segments in waveguide and coaxial designs without filling with dielectrics, as well as with water filling, were carried out. The paper presents the frequency dependences of VSWR, reflection coefficient, attenuation averaged for two-line segments without filling. These data allow us to identify the systematic error of the experiment, which will allow us to correct the result for the filled segment. The analysis shows that in the unfilled segment, losses in contact connections prevail over losses in conductors. The frequency dependences of the reflection coefficient, the relative absorption power in the dielectric and the tangent of the dielectric loss angle for the experiment with water are presented. The results obtained are consistent with those published. Thus, using the considered technique, it is possible to determine the electromagnetic parameters of various liquid substances in the microwave range. Currently, the study of the use of electromagnetic waves in the microwave range (UHF (ultra-high frequencies) – 0.3-3 GHz, SHF (super-high frequencies) – 3-30 GHz) for heating various substances with suitable electro dynamic properties is continuing. Liquid substances are of particular interest in this field. Microwave radiation treatment can be used to solve the problems of disinfection of water, milk, and so on. Microwave heating can be used in the oil industry (reducing the viscosity of oily materials when pumping through pipes, melting asphalt paraffin plugs and polluting deposits in the pipes of oil wells, and so on). Most often, to determine the electrodynamic parameters of sub stances, a method of measuring characteristics is used when the sub stances under study are located inside a volumetric resonator. Despite the good accuracy, the disadvantage of this approach is obvious - it is impossible to adjust the measurement frequency parameters in a sufficiently wide operating range during experimental studies.

NATURAL ELECTROMAGNETIC MODES OF A COMPOSITE OPEN STRUCTURE INVOLVING A PERFECTLY CONDUCTING STRIP GRATING, AN INHOMOGENEOUS FERRITE LAYER, AND A MONOLAYER OF GRAPHENE

Subject and Purpose. Сonsidered are the natural modes and their correspondent eigenfrequencies of a composite structure which is nonuniform along one of the coordinates and consists of a lossy ferromagnetic layer placed in a static magnetic field. The layer involves a perfectly conducting strip grating at one of its boundaries and a graphene monolayer at the other. Methods and Methodology. The above stated problem can be approached within the analytical regularization procedure developed for dual series equations. The latter concern a broad class of diffraction problems which include, in particular, the diffraction of monochromatic plane waves on strip gratings placed at the boundary of a gyromagnetic medium. The amplitudes of the electromagnetic eigenmodes can be obtained from the infinite set of homogeneous linear algebraic equations solvable within a truncation technique. The roots of the system’s determinant represent complex-valued eigenfrequencies of the system under investigation. The material parameters adopted in our computations for the ferromagnetic layer correspond to such of yttrium iron garnet. Results. A number of numerical programs have been developed which permit analyzing the dependences of wave field eigenfunctions and complex eigenfrequencies upon geometrical parameters of the structure (such as grating slot width and period, and thickness of the lossy layer), as well as on electrodynamic parameters of the ferromagnet and graphene characteristics, specifically the chemical potential and relaxation energy of electrons. A number of behavioral regularities have been established, as well as the effect of non-uniformity of ferrite layer parameters upon the structure’s eigenfrequencies and wave field eigenfunctions. Conclusions. The structure under study has been shown to be is an open oscillatory system with a set of complex-valued natural frequencies demonstrating finite points of accumulation. The real parts of these eigenfrequencies lie in a certain interval determined by characteristic frequencies of the ferrite layer, while the imaginary parts are negative, such that the correspondent natural modes show an exponential decay with time. The grating edges represent the mirrors which the natural surface oscillations are reflected from, being supported at that by the ferromagnetic medium. The results obtained in this paper can be useful for creating the elemental base for microwave devices and the devices themselves.

Development and research of a slow-wave system for a miniature W-band multibeam traveling wave lamp

The results of the development of a meander-type slow-wave system (SS) with metal supports for a miniature high-power W-band traveling wave lamp (TWT) with two ribbon electron beams are presented. Using a three-dimensional finite element software package, the electrodynamic parameters of the GS were studied. A two-section model of a TWT amplifier with a discontinuity has been developed to prevent self-excitation. Three-dimensional modeling of electron-wave interaction was carried out. It was found that with a total beam current of 200 mA in linear mode, the gain exceeds 30 dB in the frequency band 95.4...97.75 GHz, and the output power in saturation mode reaches 120 W. A technology for manufacturing SS based on laser microprocessing of thin copper plates is proposed. Test samples of the SS were manufactured and verified using optical and scanning microscopy.

Structural study of the rare earth compounds: Sm(OH)3, NdOHCO3, CeO2, and Ho2O3, prepared by Chemical Bath Deposition, and its correlation with crystal growth mechanism

We present the preliminary theoretical-experimental study of the structural properties for rare earths: hydroxide, hydroxycarbonate and Oxide; Sm(OH)3, NdOHCO3, CeO2, and Ho2O3 powders, respectively. In the experimental preparation, Chemical Bath Deposition (CBD) technique is applied at ~20 ±2 °C. In our experimental conditions, the parameters of crystal growth are: concentration of progenitor reagents, stirring, pH and temperature, remain constant. The chemical kinetics of crystal growth is systematically examined at key synthesis steps, considering the physicochemical and electrodynamic parameters: ionic radii, electron affinity, and hydration enthalpy of the rare earth (Sm3+, Nd3+, Ce3+, and Ho3+) cation. The main objective of this report is to investigate the theoretical-experimental correlation associated with the experimental conditions and the physicochemical parameters in the synthesis of hydroxide, hydrocarbonates and oxide. The crystallographic study of the powders is carried out using the X-ray Diffraction (XDR) technique. Analyzing the crystal phase, it is found that Sm(OH)3 and NdOHCO3 present hexagonal crystal phase, CeO2 and Ho2O3 are identified cubic crystal structure. The quantified grain size turns out to be: Sm(OH)3: ~1.40 - 2.03 nm, NdOHCO3: ~14.33 - 22.25 nm; CeO2: ~1.65 - 3.05 nm; and Ho2O3: ~3.72 - 6.08 nm. The Dislocation density (?) is: Sm(OH)3: ~2.47 - 5.10×1017 lines/m2; NdOHCO3: 2.01 - 4.68×1015 lines/m2; CeO2: 1.07 - 3.67×1017 lines/m2.

Physical Aspects of Chemical Carcinogenesis

This study investigated the effects of chemical carcinogenesis induced by 7, 12-dimethylbenz (α) anthracene (DMBA) in mice. The respiratory activity of isolated mitochondria in mouse livers was investigated at various times after the subcutaneous administration of DMBA. Our findings indicated that DMBA derivatives did not exhibit damaging effects on mitochondrial membranes. On the contrary, they showed a stimulating effect on the phosphorylation process compared with the control. This paper discusses the possible role of coherent electromagnetic radiation in biological systems. Additionally, data on the non-chemical interactions between isolated mitochondria and the material (plexiglass and quartz) of the incubation cells were considered. Carcinogenesis was previously considered an exclusive process of biochemical and genetic disorders. However, recent studies have increasingly focused on the physical aspects of carcinogenesis, such as the influence of various wavelengths of electromagnetic radiation on biological systems, the special energy organization of the intracellular space associated with the architectonics of mitochondria and microtubules, and the generation of coherent electromagnetic waves. It was assumed that the biological features of the malignant cells were due to the violation of the electrodynamic parameters of the intracellular space, and the initiating factor was the intrinsic emission of carcinogenic substances. The results of this study indicated that non-chemical factors influenced the mitochondrial poly-enzyme system and confirmed the importance of the non-chemical effect of a carcinogen on bio-objects by examining respiration and phosphorylation of isolated mouse liver mitochondria at various times after the subcutaneous injection of DMBA.

Measurements of the Electrodynamic Parameters of a Cylindrical RF-Cavity with Stainless-Steel Samples

Measurements of the Electrodynamic Parameters of a Cylindrical RF-Cavity with Stainless-Steel Samples

Spectral characteristics of an open resonator with a plasma cylinder

Statement of the problem. Approximate models of open structures with plasma inclusion describe the spectral characteristics of such electrodynamic objects rather roughly. In this regard, it is of interest to study them on the basis of a rigorous model in order to clarify the features of their behavior on various geometric and electrodynamic parameters. Objective. To propose a methodology for modeling the spectral and diffraction characteristics of open resonators containing inhomogeneous inclusions, allowing a unified approach to the study of their electrodynamic characteristics. Results. Analytical physical and mathematical models of the spectral characteristics of the resonator based on the calculation of the matrix operator function in the case of an inhomogeneous dielectric inclusion are presented. Practical significance. It is of great interest for various areas of plasma physics and biophysics to study the spectral and diffraction characteristics of the open resonators containing various inhomogeneous inclusions, the material parameters of which depend on spatial coordinates or on the frequency parameters of the structure. The results obtained can be used in the study of the properties of such objects.

Enhanced electrodynamic properties acrylonitrile butadiene styrene composites containing short-chopped recycled carbon fibers and magnetite

The development of new polymer composites with conductive and magnetic fillers that are compatible with additive manufacturing (AM) is a highly topical issue. In this work, we discussed the effect of short virgin/reclaimed carbon fibers and magnetite on the electrodynamic properties of acrylonitrile butadiene styrene (ABS) in the X-band frequencies. The choice of selected frequency range is connected with a large number of various radio engineering systems operating with these frequencies, including radar and satellite communication systems. Composites with the addition of short carbon fiber and magnetite exhibit excellent shielding factors ranging from 37.9 to 33.7 dB at frequencies 8–12 GHz. A detailed study of the electrodynamic parameters revealed the attractive properties of reclaimed carbon fiber as a component of shielding materials, especially with the simultaneous addition of magnetite. It should be noted that for this particular composite, the permittivity imaginary part increase was up to −23.96 (88 %) at 8 GHz compared to the virgin carbon fiber and magnetite composite.

Ultrahigh-Frequency Hop Dryer with Tiered Resonators

Introduction. From the analysis of hop dryers of different systems and designs follows the prospect of hop drying by complex influence of the energy of the electromagnetic field of ultrahigh frequency and convective heat. Aim of the Article. The article aims at developing a small-sized microwave convective hop dryer with justified parameters for intensive drying technology of freshly harvested hops. Materials and Methods. Taking into account the justified criteria for the design of a hop dryer and the analysis of existing resonators, there was proposed a methodology for the development of a hop dryer with an energy supply in an electromagnetic field, including requirements for structural design, operational and economic indicators, and technology. The electrodynamic parameters of the resonator were investigated according to the CST Studio 2017 program. Results. The dielectric parameters of hops are theoretically investigated and functional dependences on humidity at a frequency of 2,450 MHz are obtained. The dynamics of hop heating is investigated when its dielectric loss factor changes during the action of an ultrahigh frequency electromagnetic field. There has been developed a design and technological scheme of a radio-hermetic microwave convective hop dryer of continuous flow action with tiered resonators for low-power agricultural enterprises. Resonators are arranged in tiers in the screening cylindrical housing: the first and third resonators are hemispherical, and the middle one is made in the form of an ellipsoid to ensure a high electric field strength. The transportation of raw materials takes place by rotating the discs in a gentle mode. Discussion and Conclusion. The expected specific energy costs of a hop dryer with a capacity of 12–13 kg/h at the microwave generator power of 4.0 kW for drying freshly harvested hops with a humidity of 76–82% to a humidity of 11–14% are 0.30–0.33 kWh/kg. The required electric field voltage of 2 kV/cm in all three resonators is provided, therefore, disinfection of raw materials occurs at a temperature of 65–70°C for 5–6 minutes of stay in three resonators. The intensity of moisture release from hop cones during endogenous convective heating increases 5–6 times compared to the convective drying method. The introduction of microwave drying technology using a convective method of evaporation and removal of moisture from the drying chamber reduces the duration of the process, saves valuable components of cones for brewing.

Deposition of Thick SiO2 Coatings to Carbonyl Iron Microparticles for Thermal Stability and Microwave Performance.

Thick dielectric SiO2 shells on the surface of iron particles enhance the thermal and electrodynamic parameters of the iron. A technique to deposit thick, 500-nm, SiO2 shell to the surface of carbonyl iron (CI) particles was developed. The method consists of repeated deposition of SiO2 particles with air drying between iterations. This method allows to obtain thick dielectric shells up to 475 nm on individual CI particles. The paper shows that a thick SiO2 protective layer reduces the permittivity of the 'Fe-SiO2-paraffin' composite in accordance with the Maxwell Garnett medium theory. The protective shell increases the thermal stability of iron, when heated in air, by shifting the transition temperature to the higher oxide. The particle size, the thickness of the SiO2 shells, and the elemental analysis of the samples were studied using a scanning electron microscope. A coaxial waveguide and the Nicholson-Ross technique were used to measure microwave permeability and permittivity of the samples. A vibrating-sample magnetometer (VSM) was used to measure the magnetostatic data. A synchronous thermal analysis was applied to measure the thermal stability of the coated iron particles. The developed samples can be applied for electromagnetic compatibility problems, as well as the active material for various types of sensors.

Development and substantiation of the electrodynamic parameters of a continuous operation radio wave installation for the heat treatment of eggs

Introduction. The existing methods of cooking eggs in water and with steam have a high energy intensity. Currently, the problem of continuity of the technological process is still not solved. That is why, in order to reduce energy consumption, reduce water consumption and intensify the process of heat treatment of eggs, we consider it relevant to use the energy of the electromagnetic field of super high frequency (SHFEMF) in a special temperature regime without using water.Methodology. Three-dimensional modeling of the installation was carried out in the Compass 18.0 program, the justification of the heat treatment modes was carried out by analytical methods, to identify the optimal parameters (energy consumption and temperature regime) of the proposed installation, second-degree least squares polynomials were used, in particular, a rotatable second-order planning matrix, statistical analysis of the matrix was carried out in a software package for statistical analysis Statistica 12, confirmation of analytical data with empirical data was carried out in the CST Microwave Studio program for three-dimensional modeling of electromagnetic field propagation processes in the Eigenmode calculation module, where patterns of electric and magnetic field intensity distribution in a spherical resonator were studied.Results. The structural design of the conveyortype radio wave installation allows for heat treatment of eggs when moving in dielectric cups through slotted spherial resonators. The borehole of the process is less than 0.5 due to the location of the cups in the resonators and between them in relation 4:9. The value of the resonator's own Q-factor reaches 8800. The visualization in the program shows a uniform distribution of the electric field in the resonator, with a voltage of 1.5–3 kV/cm, which ensures high sterility of the product. From the regression models compiled on the basis of the matrix of rotatable planning of the second-order experiment, it follows that the effective duration of exposure to EMF is 154 s, the specific energy costs are equal to 143 Wh/kg. The speed of rotation of the conveyor gear motor is 0.4 rpm.

Comparative analysis of microwave granulators implementing electrophysical methods for processing secondary agricultural raw materials

Introduction. A promising direction for granulation of combined secondary raw materials of animal and vegetable origin is high-temperature molding of granules under the influence of an electromagnetic field of super highfrequency (SHF-EMF), which improves the microbiological parameters of protein feed.Results. Microwave granulators of multicomponent raw materials containing different design versions of resonators have been developed— for example, toroidal, cylindrical and ellipsoidal resonators. The electrodynamic parameters of these resonators are determined and the technical characteristics of the granulators are described. The required specific heat for the processing of secondary fat-containing raw materials has been calculated. With a granulator capacity of 200 kg/h and a specific power of the microwave generator of 1.4–2 W/g, the duration of exposure to the raw material weighing 0.8–1 kg in the resonator chamber should be 10–12 s. This ensures the minimum specific energy costs of 0.06 kW·h/kg.

Optical Properties of LiGdF4 Single Crystal in the Terahertz and Infrared Ranges

The basic mechanisms of absorption of THz range radiation in optically perfect LiGdF4 single crystals were studied using the broadband experimental data and the dielectric response function analysis within the harmonic oscillator model. The polarized IR reflection spectra have allowed one to determine the phonon contribution in the absorption coefficient in the THz range, while transmission spectra in the THz range were used to obtain the birefringence value and the effects of various mulitparticle processes. Additionally, we established the optical and electrodynamic parameters of the LiGdF4 single crystal, which are necessary for the design of nonlinear optical devices.

COMPARATIVE EVALUATION OF THE STRUCTURAL DESIGN OF MICROWAVE CONVECTIVE HOP DRYERS

In hop production, the main scientific problem is the low energy efficiency of hop dryers with convective heat supply and the absence of small-sized mobile continuous-flow hop dryers for farms that ensure the preservation of the consumer properties of hops at reduced operating costs. In order to reduce the operating costs of drying hops, work is being carried out aimed at clarifying the drying modes that contribute to the best preservation of consumer characteristics, and the improvement of technologies and technical means that would reduce operating costs. A new method of drying hops by ultra-high-frequency energy supply deserves attention. (Research purpose) The research purpose is revealing the effectiveness of an ultrahigh-frequency convective hop dryer of continuous-flow action by evaluating the developed structural designs of hop dryers with metal-dielectric resonators that ensure uniform drying and disinfection of freshly harvested hops and electromagnetic safety without a shielding housing at reduced operating costs in the conditions of hop farms. (Materials and methods) Carried out three-dimensional modeling of the structural designs of hop dryers in the Compass 20 program, determined the electrodynamic parameters of the ”generator-resonator“ system in CST Microwave Studio. (Results and discussion) Solved the problem of optimizing the structural design and dimensions of metal-electric resonators. It was shown that the main criteria are the correctly agreed parameters of the electrodynamic system ”generator-resonator“: the intrinsic Q-factor of the resonator, the voltage of the electric field, its uniformity of distribution, the power of the radiation flux, the volume of the resonator. The electro-dynamic parameters of 11 hop dryers with different designs of resonators were analyzed: hemispherical, semi-cylindrical, cylindrical, toroidal, prismatic, ellipsoid and others. (Conclusions) It was found that toroidal and hemispherical resonators have a maximum intrinsic Q-factor of up to 8000. It was determined during the evaluation of deviations from the average value of the intervals of variation of the criteria that hop dryers with resonators in the form of a paraboloid and hyperboloid, and semi-cylindrical, are effective.

SCIENTIFIC AND TECHNICAL BASIS FOR THE DEVELOPMENT OF INSTALLATIONS WITH MICROWAVE POWER SUPPLY FOR PROCESSING RAW MATERIALS AT AGRICULTURAL ENTERPRISES

The developed methodology of designing installations with microwave power supply for heat treatment of raw materials of agricultural enterprises is described. The scientific problem is the low energy efficiency of installations designed for heat treatment of raw materials with steam-water mixture, convective heat supply, the absence of continuous-flow installations for farms that ensure the preservation of consumer properties of the heat-treated product at reduced operating costs. (Research purpose) The research purpose is developing the scientific and technical foundations of installations with microwave power supply for processing raw materials at agricultural enterprises. (Materials and methods) Carried out three-dimensional modeling of the structural design of the installations in the Compass 20 program, determined the electrodynamic parameters of the “generator-resonator” system in the CST Microwave Studio program. (Results and discussion) Resonators of different structural designs have been developed for different types of raw materials, in which electromagnetic safety is ensured by forbidden waveguides, decelerating systems in the form of a chain of connected resonators, comb, cylindrical spiral, rod ring, counter pins. In resonators with curved surfaces, several magnetrons of the same frequency or operating at close frequencies with dissectors were used to change the frequency of the generator and increase the number of types of vibrations, and mixing, transporting mechanisms that allow maintaining the well of the technological process less than 0.5 and observing the dimensions of the raw materials in accordance with the depth of penetration of the wave. It was found that when using several magnetrons, the concentration of the electromagnetic field energy in the resonator volume and the reduction of radiation losses are achieved using ceramic reflectors. The values of the intrinsic Q-values of the resonators were determined to evaluate the thermal efficiency coefficient. (Conclusions) Using the examples of an animal colostrum defroster, instant milk pasteurizer and a three-section hop dryer with air-cooled magnetrons, the implementation of the scientific and technical fundamentals of designing microwave equipment for processing raw materials of agricultural enterprises was shown. It was revealed that they provide ways to achieve a continuous mode of operation of the equipment in compliance with electromagnetic safety without a shielding housing by implementing metal-dielectric resonators with decelerating systems and ceramic reflectors with an optimal arrangement of waveguides with air-cooled magnetrons on the curved surfaces of the resonators.