Subject and Purpose. Special features of all-dielectric electromagnetic analogues of topological insulators (TI) in the microwave range are considered, aiming at studying the influence of geometrical and constitutive parameters of TI elements on the dispersion properties of topological insulators based on a two-dimensional double-periodic array of dielectric elements. Methods and Methodology. The evaluation of dispersion properties and electromagnetic field spatial distribution patterns for topological insulators is performed using numerical simulation programs. Results. The electromagnetic analogue of a topological insulator based on a double-periodic array of elliptical quartz cylinders has been considered. By numerical simulation, it has been demonstrated that the electromagnetic properties of the structure are controllable by changing the quartz uniaxial anisotropy direction without any changes in other parameters. A combined topological insulator made up of two adjoining ones differing in shapes of their unit cells has been considered with the numerical demonstration that frequencies of surface states are controllable by choosing the quartz uniaxial anisotropy direction. It has been shown that it is at the interface of two different in shape unit cells that the electromagnetic field concentration at a surface state frequency takes place. Conclusion. A possibility has been demonstrated of controlling microwave electromagnetic properties of topological insulators by changing their geometric parameters and permittivity of the constituents. From a practical point of view, topological insulators can be used as components of microwave transmission lines and devices featuring very small propagation loss.
{"title":"Dispersion properties of artifi cial topological insulators based on an infi nite double-periodic array of elliptical quartz elements","authors":"L. Ivzhenko, S. Polevoy, E. Odarenko, S. Tarapov","doi":"10.15407/rej2021.03.011","DOIUrl":"https://doi.org/10.15407/rej2021.03.011","url":null,"abstract":"Subject and Purpose. Special features of all-dielectric electromagnetic analogues of topological insulators (TI) in the microwave range are considered, aiming at studying the influence of geometrical and constitutive parameters of TI elements on the dispersion properties of topological insulators based on a two-dimensional double-periodic array of dielectric elements. Methods and Methodology. The evaluation of dispersion properties and electromagnetic field spatial distribution patterns for topological insulators is performed using numerical simulation programs. Results. The electromagnetic analogue of a topological insulator based on a double-periodic array of elliptical quartz cylinders has been considered. By numerical simulation, it has been demonstrated that the electromagnetic properties of the structure are controllable by changing the quartz uniaxial anisotropy direction without any changes in other parameters. A combined topological insulator made up of two adjoining ones differing in shapes of their unit cells has been considered with the numerical demonstration that frequencies of surface states are controllable by choosing the quartz uniaxial anisotropy direction. It has been shown that it is at the interface of two different in shape unit cells that the electromagnetic field concentration at a surface state frequency takes place. Conclusion. A possibility has been demonstrated of controlling microwave electromagnetic properties of topological insulators by changing their geometric parameters and permittivity of the constituents. From a practical point of view, topological insulators can be used as components of microwave transmission lines and devices featuring very small propagation loss.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Nikolaiev, V. Pozhar, M. Dzyubenko, K. Nikolaiev
Subject and Purpose. The article is concerned with the spectral-luminescent and lasing characteristics of the radiation from solid-state active media based on polyurethane activated by a binary mixture of dyes. The purpose of these studies is to demonstrate a possibility of the spectral range expansion of the emission from solid-state dye lasers with polyurethane active elements. Methods and Methodology. Specially prepared samples of polyurethane active media having the same donor (Rhodamine 6G) concentration but various acceptor (Sulforhodamine 101) concentrations are experimentally studied for their spectral-luminescent and lasing characteristics. Results. The main spectroscopic characteristics of Rhodamine 6G and Sulforhodamine 101 in polyurethane have been measured, the nonradiative energy transfer parameters in this molecular pair estimated. It has been demonstrated that the matrix emission spectrum can be purposefully transformed by selection of relative concentrations of dyes in the mixture. In a broadband resonator, either a single- or two-band emission with different positions and various intensities of spectral bands is observed depending on the acceptor concentration. In a dispersive resonator under the same conditions, the tuning range of the lasing spectrum expands and extends to the longer wavelengths. Conclusion. The prospects of using donor-acceptor dye mixtures for improving spectral characteristics of polyurethane active elements in solid-state dye lasers have been confirmed. It has been shown that signatures of the emission characteristics of these media are governed by the mechanism of the excitation energy transfer between dye molecules. Lasing has been obtained on polyurethane matrices with the emission wavelength tuning throughout the “green-red” region of the spectrum.
{"title":"Active media based on polyurethane doped with a binary dye mixture","authors":"S. Nikolaiev, V. Pozhar, M. Dzyubenko, K. Nikolaiev","doi":"10.15407/rej2021.03.024","DOIUrl":"https://doi.org/10.15407/rej2021.03.024","url":null,"abstract":"Subject and Purpose. The article is concerned with the spectral-luminescent and lasing characteristics of the radiation from solid-state active media based on polyurethane activated by a binary mixture of dyes. The purpose of these studies is to demonstrate a possibility of the spectral range expansion of the emission from solid-state dye lasers with polyurethane active elements. Methods and Methodology. Specially prepared samples of polyurethane active media having the same donor (Rhodamine 6G) concentration but various acceptor (Sulforhodamine 101) concentrations are experimentally studied for their spectral-luminescent and lasing characteristics. Results. The main spectroscopic characteristics of Rhodamine 6G and Sulforhodamine 101 in polyurethane have been measured, the nonradiative energy transfer parameters in this molecular pair estimated. It has been demonstrated that the matrix emission spectrum can be purposefully transformed by selection of relative concentrations of dyes in the mixture. In a broadband resonator, either a single- or two-band emission with different positions and various intensities of spectral bands is observed depending on the acceptor concentration. In a dispersive resonator under the same conditions, the tuning range of the lasing spectrum expands and extends to the longer wavelengths. Conclusion. The prospects of using donor-acceptor dye mixtures for improving spectral characteristics of polyurethane active elements in solid-state dye lasers have been confirmed. It has been shown that signatures of the emission characteristics of these media are governed by the mechanism of the excitation energy transfer between dye molecules. Lasing has been obtained on polyurethane matrices with the emission wavelength tuning throughout the “green-red” region of the spectrum.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Velichko, A. Matveev, D. Bychkov, V. Ivanov, V. Tsymbal, O. Gavrilenko
Subject and Purpose. The paper addresses interaction processes going in the ocean–atmosphere system and is concerned with their research by the method of radar remote sensing. Specifically, the matter of concern is the detection and parameter estimation of long waves, including nonlinear ones, on the ocean surface. Methods and Methodology. In August 1988, a series of successive radar surveys of long surface wave manifestations on the Pacific Ocean surface was carried out in the 3 cm wave range by means of an airborne X-band radar system “Analog”. The analysis of the results includes estimation of both spatial and frequency features of the detected long-wave packets and, also, a comparison of the measurement results with model calculations performed in the framework of theory of radio wave scattering by the sea surface in the presence of seismic wave effects. Results. Radar images of wave packets of long surface waves in the open ocean have been obtained. From the imaging data, the spatial scale (5…10 km) of these waves, the lengths (1…5 km) of wave packet components and the wave packet velocity (6.1 m/s) have been derived. Analysis has been given to the nonlinear form of wave packet components, and their amplitudes have been estimated by comparing the experimental and theoretically obtained radio contrasts. The bathymetry of the surface-wave track has been performed to suggest that the observed wave packet represents a set of solitons generated by a seismic impact with the further underwater collapse. Conclusions. A possibility has been demonstrated for monitoring wave packets of long surface waves in their propagation dynamics. The experiments of the sort for gaining a deeper insight into the ocean–atmosphere interaction physics can be conducted by means of not only airborne but also spaceborne radar systems with allowance made for the rate of surveys in both time and space.
{"title":"Radar monitoring of long surface waves in the pacific ocean","authors":"S. Velichko, A. Matveev, D. Bychkov, V. Ivanov, V. Tsymbal, O. Gavrilenko","doi":"10.15407/REJ2021.01.003","DOIUrl":"https://doi.org/10.15407/REJ2021.01.003","url":null,"abstract":"Subject and Purpose. The paper addresses interaction processes going in the ocean–atmosphere system and is concerned with their research by the method of radar remote sensing. Specifically, the matter of concern is the detection and parameter estimation of long waves, including nonlinear ones, on the ocean surface. Methods and Methodology. In August 1988, a series of successive radar surveys of long surface wave manifestations on the Pacific Ocean surface was carried out in the 3 cm wave range by means of an airborne X-band radar system “Analog”. The analysis of the results includes estimation of both spatial and frequency features of the detected long-wave packets and, also, a comparison of the measurement results with model calculations performed in the framework of theory of radio wave scattering by the sea surface in the presence of seismic wave effects. Results. Radar images of wave packets of long surface waves in the open ocean have been obtained. From the imaging data, the spatial scale (5…10 km) of these waves, the lengths (1…5 km) of wave packet components and the wave packet velocity (6.1 m/s) have been derived. Analysis has been given to the nonlinear form of wave packet components, and their amplitudes have been estimated by comparing the experimental and theoretically obtained radio contrasts. The bathymetry of the surface-wave track has been performed to suggest that the observed wave packet represents a set of solitons generated by a seismic impact with the further underwater collapse. Conclusions. A possibility has been demonstrated for monitoring wave packets of long surface waves in their propagation dynamics. The experiments of the sort for gaining a deeper insight into the ocean–atmosphere interaction physics can be conducted by means of not only airborne but also spaceborne radar systems with allowance made for the rate of surveys in both time and space.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. Smoke, fog, avalanches, debris of collapsed structures and other optically opaque obstacles in both natural and man-made disasters make optical sensors useless for detecting victims. Electromagnetic waves of the decimeter range penetrate well almost all obstacles, reflect from the trapped people and return to the radar receiver. Due to the breathing and heartbeat, the human-reflected sounding signals get the Doppler phase modulation, which is an information signal. These information signals and their properties provide the subject matter for the present research with the aim to create optimal methods and algorithms of random event processing for the prompt location of survivors by rescuers. Method and Methodology. The method of stochastic analysis of the fluctuation Doppler spectra of reflected sounding signals shows that the information signals have properties of conditional Markov processes. Results. The problem of optimal nonlinear filtering of conditional Markov processes entering the radar signal processing unit has been examined closely. An optimal adaptive filter has been proposed to reduce the masking effect of interferences caused by non-stationary noises and sounding signal reflections from stationary objects. The optimality criterion is the minimum mean square error function whose current value is evaluated in real time during the filtering process as the statistics is accumulated. The filter coefficients are calculated by the recurrent, steepest descent algorithm. The real-time work is carried out through the use of fast Fourier transform algorithms. Conclusion. The structure of the optimal adaptive filter to be built into the radar signal processing unit has been developed. Real radar signals have shown that the optimal filtering during the signal processing in systems designed for detecting live people by their breathing and heartbeat facilitates the interpretation of the observed signals. Some spectra of real signals generated by human breathing and heartbeat are presented.
{"title":"Optimal nonlinear fi ltering of stochastic processes in rescue radar","authors":"O. Sytnik","doi":"10.15407/rej2021.03.018","DOIUrl":"https://doi.org/10.15407/rej2021.03.018","url":null,"abstract":"Subject and Purpose. Smoke, fog, avalanches, debris of collapsed structures and other optically opaque obstacles in both natural and man-made disasters make optical sensors useless for detecting victims. Electromagnetic waves of the decimeter range penetrate well almost all obstacles, reflect from the trapped people and return to the radar receiver. Due to the breathing and heartbeat, the human-reflected sounding signals get the Doppler phase modulation, which is an information signal. These information signals and their properties provide the subject matter for the present research with the aim to create optimal methods and algorithms of random event processing for the prompt location of survivors by rescuers. Method and Methodology. The method of stochastic analysis of the fluctuation Doppler spectra of reflected sounding signals shows that the information signals have properties of conditional Markov processes. Results. The problem of optimal nonlinear filtering of conditional Markov processes entering the radar signal processing unit has been examined closely. An optimal adaptive filter has been proposed to reduce the masking effect of interferences caused by non-stationary noises and sounding signal reflections from stationary objects. The optimality criterion is the minimum mean square error function whose current value is evaluated in real time during the filtering process as the statistics is accumulated. The filter coefficients are calculated by the recurrent, steepest descent algorithm. The real-time work is carried out through the use of fast Fourier transform algorithms. Conclusion. The structure of the optimal adaptive filter to be built into the radar signal processing unit has been developed. Real radar signals have shown that the optimal filtering during the signal processing in systems designed for detecting live people by their breathing and heartbeat facilitates the interpretation of the observed signals. Some spectra of real signals generated by human breathing and heartbeat are presented.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. The paper investigates tropospherically caused fluctuations of signals from the GPS navigation system while the satellite is beyond the radio horizon. The intensity of GPS signal fluctuations under the influence of meteorological factors is studied, too. The purpose of the work is to determine relationship between the intensity of GPS signal fluctuations and the meteorological conditions when satellite elevation angles are small. Methods and Methodology. The methodology of the work is based on the search for the intensity of amplitude fluctuations of GPS satellite’s signals depending on the meteorological situation. The measurement approach is registration of the GPS satellite’s signal level just before the satellite crosses the horizon. The data processing after a series of experimental studies is based on the extraction of tropospheric fluctuations from the complete GPS signal by the moving average method. Results. Experimental studies of the turbulent component of signals from GPS satellites at low elevation angles have been carried out. It has been revealed that a conventional elevation boundary below which the tropospheric influence is predominant can be established due to the synchronism property which the orbits of the GPS satellites hold. It has been shown that variations in the mean square deviation (MSD) of GPS signal fluctuations caused by the troposphere and extracted from the complete signal are consistent with meteorological parameter changes. Conclusion. Analysis has been carried out to show that a meteorological dependence of the MSD statistics of GPS signal tropospheric fluctuations exists. The intensity of fluctuations rises with the convective activity in the troposphere. The conducted experiments suggest that periods of increased turbulence in the atmosphere can be detected with the use of GPS signals. For this purpose, the optical methods will not do.
{"title":"Investigation of gps signal amplitude fluctuations depending on meteorological factors when passing through a turbulent atmosphere at low elevation angles over the land","authors":"Усикова Нан України","doi":"10.15407/REJ2021.01.020","DOIUrl":"https://doi.org/10.15407/REJ2021.01.020","url":null,"abstract":"Subject and Purpose. The paper investigates tropospherically caused fluctuations of signals from the GPS navigation system while the satellite is beyond the radio horizon. The intensity of GPS signal fluctuations under the influence of meteorological factors is studied, too. The purpose of the work is to determine relationship between the intensity of GPS signal fluctuations and the meteorological conditions when satellite elevation angles are small. Methods and Methodology. The methodology of the work is based on the search for the intensity of amplitude fluctuations of GPS satellite’s signals depending on the meteorological situation. The measurement approach is registration of the GPS satellite’s signal level just before the satellite crosses the horizon. The data processing after a series of experimental studies is based on the extraction of tropospheric fluctuations from the complete GPS signal by the moving average method. Results. Experimental studies of the turbulent component of signals from GPS satellites at low elevation angles have been carried out. It has been revealed that a conventional elevation boundary below which the tropospheric influence is predominant can be established due to the synchronism property which the orbits of the GPS satellites hold. It has been shown that variations in the mean square deviation (MSD) of GPS signal fluctuations caused by the troposphere and extracted from the complete signal are consistent with meteorological parameter changes. Conclusion. Analysis has been carried out to show that a meteorological dependence of the MSD statistics of GPS signal tropospheric fluctuations exists. The intensity of fluctuations rises with the convective activity in the troposphere. The conducted experiments suggest that periods of increased turbulence in the atmosphere can be detected with the use of GPS signals. For this purpose, the optical methods will not do.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Eremenko, V. Pashynska, K. Kuznetsova, O. Shubnyi, N. Sklyar, A. Martynov
Subject and Purpose. This study focuses on the original waveguide-differential dielectrometer designed for complex permittivity measurements of high-loss liquids in the microwave range towards the determination of pharmaceutical ingredient concentrations in water solutions at room temperature. The suitability of the device and effectiveness of the dielectrometry method are tested on such pharmaceutical ingredients as lincomycin and levofloxacin over a wide range of concentrations. Methods and Methodology. The main idea of the method consists in that the complex propagation coefficients of the HE11 wave are obtained from the amplitude and phase shift differences acquired by the wave after it has passed through the two measuring cells of the waveguide-differential dielectrometer. Results. We have shown that the proposed dielectometry method allows a real-time determination of pharmaceutical ingredient concentrations in water solution by measuring the wave attenuation and phase shift differences. We have found that unless concentrations of pharmaceutical ingredients are low, few free water molecules in water solution are bound to the pharmaceutical ingredients. The number of free water molecules in solution decreases as the concentration of pharmaceutical ingredients rises. Conclusion. The current study confirms that the dielectometry method and the device developed provide effective determination of pharmaceutical ingredient concentrations in water solutions.
{"title":"Microwave dielectrometer application to antibiotic concentration control in water solution","authors":"Z. Eremenko, V. Pashynska, K. Kuznetsova, O. Shubnyi, N. Sklyar, A. Martynov","doi":"10.15407/rej2021.03.030","DOIUrl":"https://doi.org/10.15407/rej2021.03.030","url":null,"abstract":"Subject and Purpose. This study focuses on the original waveguide-differential dielectrometer designed for complex permittivity measurements of high-loss liquids in the microwave range towards the determination of pharmaceutical ingredient concentrations in water solutions at room temperature. The suitability of the device and effectiveness of the dielectrometry method are tested on such pharmaceutical ingredients as lincomycin and levofloxacin over a wide range of concentrations. Methods and Methodology. The main idea of the method consists in that the complex propagation coefficients of the HE11 wave are obtained from the amplitude and phase shift differences acquired by the wave after it has passed through the two measuring cells of the waveguide-differential dielectrometer. Results. We have shown that the proposed dielectometry method allows a real-time determination of pharmaceutical ingredient concentrations in water solution by measuring the wave attenuation and phase shift differences. We have found that unless concentrations of pharmaceutical ingredients are low, few free water molecules in water solution are bound to the pharmaceutical ingredients. The number of free water molecules in solution decreases as the concentration of pharmaceutical ingredients rises. Conclusion. The current study confirms that the dielectometry method and the device developed provide effective determination of pharmaceutical ingredient concentrations in water solutions.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. The elucidation of the molecular mechanisms of action of biomolecules is necessary for the development of state-of-the-art means of diagnosing and treatment. Dielectric studies in the millimeter wave range are effective for puzzling out the nature of the interaction of biomolecules with a surrounding aqueous solvent. Flavin mononucleotide (FMN), which can kill microorganisms and destroy cancer cells, is of particular interest. The aim of the work is to recognize hydration effects (changes in the state of water molecules) in FMN solutions. Methods and Methodology. The complex dielectric permittivity (CDP) is measured in the EHF range. Knowing the difference between the CDP of FMN solution and the CDP of water we find the difference, D es , between the effective dielectric permittivities in terms of the Debye theory of polar liquids. Since the relaxation time of dipoles of bound water is one or two orders of magnitude longer than that of free water, the amount of the difference D es characterizes the hydration of biomolecules. At low concentrations, this difference is proportional to the number of bound water molecules. Results. It has been shown that approximately18 water molecules are bound to the FMN molecule. Groups of atoms as the most probable hydration centers (primarily due to the hydrogen bonds) have been indicated. As the pH decreases, the number of water molecules bound to the Flavin mononucleotide increases to 21. The study of the FMN–DNA solution has shown that one nucleotide accounts for 25–26 bound water molecules in total. However, composing hydration numbers assumes a quantity of components less than 20. An assumption is made that the additional components are due to the cooperative nature of the hydration, leading to the fact that even if some solvent molecules do not come into a direct contact with hydration centers, they are under the influence of biomolecules all the same. Conclusion. Extremely-high-frequency dielectrometry is an effective method of research into the interaction of biomolecules with a water-ionic solvent. A FMN hydration model has been proposed, which indicates probable hydration centers and tells a measure of their effect on the solvent. It has been found that the FMN with DNA interaction increases the number of bound water molecules per one nucleotide of the DNA. The obtained results have been compared to the existing models of the DNA with FMN interaction.
{"title":"Dielectrometry of hydration of fl avin mononucleotide and DNA","authors":"V. Kashpur, O. Khorunzhaya, D. Pesina","doi":"10.15407/rej2021.03.046","DOIUrl":"https://doi.org/10.15407/rej2021.03.046","url":null,"abstract":"Subject and Purpose. The elucidation of the molecular mechanisms of action of biomolecules is necessary for the development of state-of-the-art means of diagnosing and treatment. Dielectric studies in the millimeter wave range are effective for puzzling out the nature of the interaction of biomolecules with a surrounding aqueous solvent. Flavin mononucleotide (FMN), which can kill microorganisms and destroy cancer cells, is of particular interest. The aim of the work is to recognize hydration effects (changes in the state of water molecules) in FMN solutions. Methods and Methodology. The complex dielectric permittivity (CDP) is measured in the EHF range. Knowing the difference between the CDP of FMN solution and the CDP of water we find the difference, D es , between the effective dielectric permittivities in terms of the Debye theory of polar liquids. Since the relaxation time of dipoles of bound water is one or two orders of magnitude longer than that of free water, the amount of the difference D es characterizes the hydration of biomolecules. At low concentrations, this difference is proportional to the number of bound water molecules. Results. It has been shown that approximately18 water molecules are bound to the FMN molecule. Groups of atoms as the most probable hydration centers (primarily due to the hydrogen bonds) have been indicated. As the pH decreases, the number of water molecules bound to the Flavin mononucleotide increases to 21. The study of the FMN–DNA solution has shown that one nucleotide accounts for 25–26 bound water molecules in total. However, composing hydration numbers assumes a quantity of components less than 20. An assumption is made that the additional components are due to the cooperative nature of the hydration, leading to the fact that even if some solvent molecules do not come into a direct contact with hydration centers, they are under the influence of biomolecules all the same. Conclusion. Extremely-high-frequency dielectrometry is an effective method of research into the interaction of biomolecules with a water-ionic solvent. A FMN hydration model has been proposed, which indicates probable hydration centers and tells a measure of their effect on the solvent. It has been found that the FMN with DNA interaction increases the number of bound water molecules per one nucleotide of the DNA. The obtained results have been compared to the existing models of the DNA with FMN interaction.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. The article is devoted to the radio recognition of moving waterborne objects (sea-going ships). The problem lies in the lack of radar signatures, which is especially true for coherent radar in continuous mode, implying that more signatures for the waterborne object recognition is highly needed. An additional signature can be gained just by means of a simple mathematical processing of target reflection signals. This is particularly important for radio recognition systems in current use because this will hardly complicate the system structure. Hence, it will not affect its cost either. Methods and Methodology. The method developed for the retrieval of an additional radar signature characteristic of waterborne objects moving across a rough sea surface is based on a simple mathematical processing of a signal reflected from the moving waterborne object and taken from the phase output of coherent radar. The method approbation is by the mathematical modeling of signals at the phase detector output in the event of three waterborne objects such that have identical scattering cross sections but different periods of the side and keel vibrations. Results. Based on the mathematical modeling results, it has been shown that each of the local scattering centers keeps the ratio of the linear speeds of side and keel vibrations approximately the same for the same object. But the employed ratio takes different values for different objects. Conclusion. Having a single standard coherent radar in continuous mode and guided by the developed methodology, one can gain an additional signature for the target recognition, which is a ratio of the linear speeds of side and keel vibrations of the target. The suggested methodology can be used for the radio recognition of waterborne objects moving across a rough sea surface.
{"title":"Additional radar signature for waterborne object recognition","authors":"V. Gorobets, M. Golovko, S. Zotov, L. Kovorotny","doi":"10.15407/rej2021.04.016","DOIUrl":"https://doi.org/10.15407/rej2021.04.016","url":null,"abstract":"Subject and Purpose. The article is devoted to the radio recognition of moving waterborne objects (sea-going ships). The problem lies in the lack of radar signatures, which is especially true for coherent radar in continuous mode, implying that more signatures for the waterborne object recognition is highly needed. An additional signature can be gained just by means of a simple mathematical processing of target reflection signals. This is particularly important for radio recognition systems in current use because this will hardly complicate the system structure. Hence, it will not affect its cost either. Methods and Methodology. The method developed for the retrieval of an additional radar signature characteristic of waterborne objects moving across a rough sea surface is based on a simple mathematical processing of a signal reflected from the moving waterborne object and taken from the phase output of coherent radar. The method approbation is by the mathematical modeling of signals at the phase detector output in the event of three waterborne objects such that have identical scattering cross sections but different periods of the side and keel vibrations. Results. Based on the mathematical modeling results, it has been shown that each of the local scattering centers keeps the ratio of the linear speeds of side and keel vibrations approximately the same for the same object. But the employed ratio takes different values for different objects. Conclusion. Having a single standard coherent radar in continuous mode and guided by the developed methodology, one can gain an additional signature for the target recognition, which is a ratio of the linear speeds of side and keel vibrations of the target. The suggested methodology can be used for the radio recognition of waterborne objects moving across a rough sea surface.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Kovalenko, S. Kalinichenko, E. Babich, F. Kivva, O. Roenko, T. Antusheva
Subject and Purpose. The present paper is concerned with the use of wave technologies in the development of antibiotics-alternative approaches for pathogenic microflora suppression. Lactobacilli strains picked in different ecological niches and their activity against pathogenic strains are studied with a focus on a targeted modification of adhesive and antagonistic properties of lactobacilli by exposing them to low-intensity electromagnetic (EM) fields and the ultrasound. Methods and Methodology. Lactobacilli picked in different ecological niches are experimentally studied, including (1) standard strains from probiotic preparations and (2) circulating strains picked in humans and bees. For the ultrasonic and electromagnetic radiation sources, G3-109 and G3-F and G4-141 and G4-142 generators are taken, respectively. The adhesive properties of Lactobacillus spp. strains and their antagonistic activity are estimated against C. diphtheriae, S. aureus and yeast-like fungi of Candida genus in aerobic and microaerophilic culture conditions. Statistical technology is employed in the data processing and analysis. Results. It has been established that L. plantarum strains picked in the gut of healthy bees are most antagonistic towards pathogens. It has been demonstrated that the priority culture conditions for lactobacilli are microaerophilic conditions simulating their stay in vivo. It has been shown that it is possible to modify properties of microorganisms by their exposure to ultrasound and low-intensity electromagnetic fields in narrow bands of the EHF range. The effect efficiency versus frequency has a dispersion character. Individual features of various pathogenic strains have been recognized. Conclusion. The obtained results open up prospects for electromagnetic and acoustic technologies in the development of safe alternative means to antagonize persisting pathogens and increase human body resilience.
{"title":"Electromagnetic and acoustic technologies in antibacterial preparation development","authors":"O. Kovalenko, S. Kalinichenko, E. Babich, F. Kivva, O. Roenko, T. Antusheva","doi":"10.15407/rej2021.04.040","DOIUrl":"https://doi.org/10.15407/rej2021.04.040","url":null,"abstract":"Subject and Purpose. The present paper is concerned with the use of wave technologies in the development of antibiotics-alternative approaches for pathogenic microflora suppression. Lactobacilli strains picked in different ecological niches and their activity against pathogenic strains are studied with a focus on a targeted modification of adhesive and antagonistic properties of lactobacilli by exposing them to low-intensity electromagnetic (EM) fields and the ultrasound. Methods and Methodology. Lactobacilli picked in different ecological niches are experimentally studied, including (1) standard strains from probiotic preparations and (2) circulating strains picked in humans and bees. For the ultrasonic and electromagnetic radiation sources, G3-109 and G3-F and G4-141 and G4-142 generators are taken, respectively. The adhesive properties of Lactobacillus spp. strains and their antagonistic activity are estimated against C. diphtheriae, S. aureus and yeast-like fungi of Candida genus in aerobic and microaerophilic culture conditions. Statistical technology is employed in the data processing and analysis. Results. It has been established that L. plantarum strains picked in the gut of healthy bees are most antagonistic towards pathogens. It has been demonstrated that the priority culture conditions for lactobacilli are microaerophilic conditions simulating their stay in vivo. It has been shown that it is possible to modify properties of microorganisms by their exposure to ultrasound and low-intensity electromagnetic fields in narrow bands of the EHF range. The effect efficiency versus frequency has a dispersion character. Individual features of various pathogenic strains have been recognized. Conclusion. The obtained results open up prospects for electromagnetic and acoustic technologies in the development of safe alternative means to antagonize persisting pathogens and increase human body resilience.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. Precipitation is the main source of agricultural land moisture. The knowledge of its amount, especially during the growing season, is important information to justify necessary agronomic and land reclamation measures. The purpose of this work is to solve by regularization the inverse problem of double-frequency sensing of precipitation in the microwave range with the signal attenuation considered and analyze the influence of radar cross-section (RCS) calculation errors and the total signal attenuation measuring precision on the rain intensity retrieval results. Methods and Methodology. Numerical simulation is used in double frequency retrievals to solve the integral scattering equation by regularization methods. Results. Numerical simulation has been performed for the rain intensity retrieval with a uniform spatial profile of rain intensity in the range 1…20 mm/h. Direct and inverse iterative procedures were used for having the signal attenuation at 0.82 and 3.2 cm operating wavelengths. It has been shown that the direct iterative procedure is less effective than the inverse one. Thus, when the rain intensity exceeds 20 mm/h or when it is within 10…20 mm/h and a rain spatial extent goes over 500 m, the direct iteration scheme causes significant errors in the rain intensity retrieval. Conclusion. The analysis of the results has shown that the use of the inverse iterative procedure makes it possible to retrieve a uniform-profile rain intensity with a 25 % error for rains with a 20 mm/h intensity and a 4 km spatial extent and ± 20 % errors in the total signal attenuation and specific RCS calculated.
{"title":"Сonsideration of the signal attenuation in double-frequency sensing for rain intensity retrieval","authors":"A. Linkova","doi":"10.15407/rej2021.03.003","DOIUrl":"https://doi.org/10.15407/rej2021.03.003","url":null,"abstract":"Subject and Purpose. Precipitation is the main source of agricultural land moisture. The knowledge of its amount, especially during the growing season, is important information to justify necessary agronomic and land reclamation measures. The purpose of this work is to solve by regularization the inverse problem of double-frequency sensing of precipitation in the microwave range with the signal attenuation considered and analyze the influence of radar cross-section (RCS) calculation errors and the total signal attenuation measuring precision on the rain intensity retrieval results. Methods and Methodology. Numerical simulation is used in double frequency retrievals to solve the integral scattering equation by regularization methods. Results. Numerical simulation has been performed for the rain intensity retrieval with a uniform spatial profile of rain intensity in the range 1…20 mm/h. Direct and inverse iterative procedures were used for having the signal attenuation at 0.82 and 3.2 cm operating wavelengths. It has been shown that the direct iterative procedure is less effective than the inverse one. Thus, when the rain intensity exceeds 20 mm/h or when it is within 10…20 mm/h and a rain spatial extent goes over 500 m, the direct iteration scheme causes significant errors in the rain intensity retrieval. Conclusion. The analysis of the results has shown that the use of the inverse iterative procedure makes it possible to retrieve a uniform-profile rain intensity with a 25 % error for rains with a 20 mm/h intensity and a 4 km spatial extent and ± 20 % errors in the total signal attenuation and specific RCS calculated.","PeriodicalId":52841,"journal":{"name":"Radiofizika i elektronika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67138440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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