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This paper is devoted to mathematical modelling of technology for organic livestock waste (OLW), for example, from poultry and horse breeding, microwave treatment. A significant improvement in the quality of OLW treatment, a decrease in energy costs and a reduction in the duration of the required thermal effect can be achieved by using environmentally friendly energy of the microwave electromagnetic field. The costs of designing, improving and optimizing microwave heating devices are significantly reduced by building and research of mathematical models of the processes occurring in the electrodynamics reactors. The most perfect, from the point of view of the possibilities of achieving the required quality indicators of OLW from poultry and horse breeding microwave treatment, are technological microwave installations and complexes, the control of which is based on the principles of adaptive organization. To organize adaptive control and management of OLW from poultry and horse breeding treatment, it is necessary to develop a multi-sensor system for controlling the temperature and humidity of the treated medium, built into the microwave complex, which directly affects the electro physical parameters of the treated medium.

We report on the numerical simulations and experimental validation of a microwave planar sensor based on two coupled rings operating in the 4&ndash, 6 GHz range. The fabricated sensor is used to characterize the dielectric permittivity of vegetable oils. We optimized the geometrical parameters in order to improve the overlap between the oil samples under study and the electric field. The experimental results showed an excellent match with the simulation results. The fabricated sensor allowed to retrieve the oil permittivity with a sensitivity of about 35 MHz per permittivity unit in the frequency range of interest. This paves the way to the realization of compact and sensitive sensors for a wide plethora of fields ranging from industry and food to chemistry and biology.

The influence of growth conditions on the carbon dendrite structure has been investigated. The threshold values of the ratio between electron temperature Te and kinetic temperature T of the gas near a needle electrode and of the discharge current density, which are necessary for dendritic growth, have been determined. It has been shown that the hexagonal structure of submicron carbon particles arises when a number of hydrocarbons are used to synthesize dendrites. It has been found that the degree of order in the carbon structure can be controlled by applying external actions at the stage of graphite particle nucleation. The characteristic frequencies of inertial actions that may be energetically appropriate must exceed 10 kHz.

Electromagnetic impact on oil reservoir manifests itself in various physical and chemical phenomena and attracts a significant scientific and technological interest. Microwave (MW) radiation heating can be more efficient for the oil recovery than heat transfer by convection or by thermal conduction. MW influence can also lead to significant changes in the physicochemical and rheological properties of oil caused by chemical processes of transformation of the oil high-molecular components such as resins and asphaltenes. The efficiency of transition-metal catalysts applied for the in-situ conversion of hydrocarbons directly in the reservoir might be significantly increased by exposing the oil formation to MW radiation. Actually, transition metals nanoparticles and their oxides are considered as active absorbers of MW radiation and; therefore, they can be used to intensify MW impact on the reservoir. Catalyst particles dispersed in the formation provide enhanced MW sweep. Taken together, the functioning of the catalysts and the effect of microwave radiation provide deep conversion of resins and asphaltenes, a decrease in the viscosity of the produced oil and an increase in oil recovery factor, along with a decrease in water cut of the well production. The present review analyzes the latest works on the combined application of microwave exposure and dispersed catalysts. In addition, this review discusses the prospects and perspectives of practical application of electromagnetic heating to enhance heavy oil recovery in the presence of nanoparticles.

A new method based on the so-called discrete geometrical invariants (DGIs) is proposed to highlight the statistical differences between random sequences that can be presented in the form of two dimensions curves. The effectiveness of the proposed method is validated experimentally. Different complex fluids (i.e. sunflower and olive oils from different producers, isopropanol (IPA), sodium chloride, glucose, and distilled water) are considered to carry out a set of measurements for identifying the differences between fluids. The experimental results are obtained by two different approaches that are based on microwave and optical characterization. Moreover, an algorithm is provided to apply the DGIs method to both types of results and, in general, to implement the identification method in an automatic way also to other fluids. The new methodology is specified by the combination of the peculiar statistical analysis with the employed experimental technique. It opens a wide scenario of practical applications in detection and identification of hidden differences between complex fluids like vegetable and industrial oils, wines, milk, etc., without having a detailed knowledge of the complicated chemical content. It is expected that the proposed methodology can be applied to different technologies and systems, such as in production of different beverages, chemical fluids and solutions.

Based on ferrocene-1,1'-diyl-bisphosphinic acids Fc[P(R)(O)OH]2 (R = H, Me, Et, Ph) in methanol, two types of electrochemically driven molecular rotors are developed. Monoanions of acids are fixed in the cis-conformation due to the presence of an intramolecular hydrogen bond, whereas dianions are fixed in the trans-conformation due to electrostatic repulsion forces. Upon the transformation of monoanions to dianions, the controlled rotation of cyclopentadienyl rings from cis to trans-conformation occurs; the reverse switching leads to the reverse rotation. In one type of rotors, the rotation is controlled by the reversible variation of the solution pH and composition in the electrochemical oxidation-re-reduction cycle of N-phe-nyl-N'-isopropyl-1,4-phenylenediamine; in the other type, the rotation is determined by the one electron oxidation-re-reduction of the ferrocene nucleus in monoanions. The latter rotor type at room temperature can operate stably only for a short time (τ< 1 s) and at longer times is irreversibly destructed during the oxidation stage.

In the work we give the results of an experiment during which carbon dendrite structures were formed in the plasma of an atmospheric-pressure gas discharge by using depolymerization products of polymer materials.

The paper studies principles of ionospheric irregularities probed using polyharmonic signals on the example of the two-frequency oscillation which is a beat signal. Authors have considered the interaction of a symmetrical two-frequency signal with an abstract resonant circuit which shows the normalized frequency dependence of the reflection coefficient, typical for resonant inhomogeneities in the form of a periodic structure in the ionosphere.

The main characteristic of the converter element in resonant microwave sensors that determines the sensitivity of the conversion is the quality factor of the resonance line. In structures with periodic inhomogeneity of the classical topology, the quality factor of the circuit at high values of the signal-to-noise ratio may turn out to be low, which entails the emergence of restrictions on the maximum achievable conversion parameters. One of the ways to increase both the Q factor and the modification of other properties of the microwave structure that affect the overall efficiency of the converter element is the use of quasiperiodic elements. The coaxial cable, where the holes in the dielectric act as inhomogeneity, is presented, forming structure with phase shift. Using the method of flow graphs, we obtained the analytical dependence of the reflection coefficient for this structure. The analysis of the frequency response of the microwave reflection coefficient was carried out for different values of the phase shift and the location of the phase shift section along the length of the cable. A numerical and physical experiments were carried out to determine the frequency dependence of the microwave reflection coefficient with a π-phase shift for various values of the automobile fuel permittivity introduced into the cells.

The Bragg microwave structures on the coaxial waveguide, constructed on the basis of the transfer optical technologies similar to the Bragg fiber grating, are considered. It is offered to use versions of such coaxial Bragg microwave structures in sensor application, in particular, creation of strain gauges, instruments for measuring dielectric constant of liquids and liquid products' level is considered. Methods for description of periodic inhomogeneous microwave structures characteristics and ways to modify the form of the frequency dependence of scattering parameters are viewed.

A new approach to teaching technical disciplines in training of Radio Engineers is proposed. The approach is based on the method of non-linear note-taking using mind maps. This method allows students to analyze and process the studied material quickly and with high quality by engaging both the left and right hemispheres of the brain in the work. The effectiveness of this approach is shown and its strengths and weaknesses are considered.

The implementation of non-absorbent polymers thermal destruction initiated by indirect heating in an intense electromagnetic microwave field using carbon thermal conversion elements is considered. Results of theoretical analysis based on mathematical modeling and experimental investigation into depolymerization of the polymer are analyzed. Polystyrene and polymethylmethacrylate are the investigated polymers; their destruction products are styrene and methyl methacrylate.

The technology of fiber Bragg gratings is used as one of the most applicable technologies for construction of fiber optic sensors and telecommunication systems. Periodic irregular wave resistance located in the guiding waveguide can be regarded as analog of the fiber Bragg grating structure in the field of radio-frequency. Coaxial waveguide can be used as a guide system, so a special case of this structure is the Bragg grating on coaxial cable. Recently, the special structure of sensors were beginning to be used with heterogeneity as a discrete phase π-shift. Based on the properties analysis of the Bragg reflection characteristics of structures with a phase shift in the optical and microwave range shown advantage of using these devices in measuring systems.