Ma Huayuan, Long Yuan, Zhong Mingshou, Li Xinghua, Xie Quanmin «Study on Ground Vibration Mode of Physical Explosion of High Pressure Natural Gas Pipeline» Акустический журнал, 65, № 5, с. pp. 583-592 (2019)

In this paper, an explosion experiment was carried out on the OD1219mm-X90-12Mpa natural gas pipeline to study the vibration hazard. Based on a series of experiments, the spatial distribution of the vibration energy was studied. The vibration distribution field was drawn by interpolation method based on re-harmonic equation and it was found that the field was non-circular symmetry. Through in-depth research, it was preliminarily proved that the vibration field had interference characteristics, which was caused by the special vibration source of the pipeline explosion. There was a significant difference in the frequency components between the interference strengthened region and the weakened region. The results shown that the strengthening effect of the interference in the 90° and 30° direction should be taken into account when evaluating the damage scope of the explosion accident. Research provided reference for safety design of parallel pipelines and buildings.

Jurkonis R., Sakalauskas A., Lukoševičius A., Maciulevičius M., Tamoši~-unas M., Šatkauskas S. «Mapping Microbubble and Ultrasound Spatio-temporal Interaction by M-mode Imaging: The Study of Feasibility» Акустический журнал, 65, № 2, с. pp. 216-225 (2019)

Ultrasound (US) and microbubble (MB) interaction is an important factor in the research of bioacoustics, as well as targeted drug and gene delivery. In this study, we demonstrate the feasibility of pulse–echo M-mode imaging system to be used for the visualization and quantification of US–MB interaction in both spatial and temporal dimensions. The system incorporates an exposure chamber with the cell–MB suspension, a 2.7 MHz focused US transducer, a US pulser–receiver and the customized LabView software. The results of cell and MB interaction obtained after M-mode image analysis have showed the US–MB interaction to be non-uniform in space and non-stationary in time. In order to quantify the spatio-temporal US–MB interaction, we have introduced the time function of spatial homogeneity dynamics. We have observed that the effective duration of interaction can be characterized at the predefined threshold of spatial homogeneity. For example, at the US excitation of 360 kPa peak negative pressure (15 bursts transmitted at 80 Hz pulse repetition frequency), the US–MB interaction persists for more than 5 seconds in the range at 4 mm depth of the exposure chamber with more than 50% of homogeneity. The system proposed in this assay is feasible for the characterization of US–MB interaction and can be exploited to optimize the MB concentration and/or the US excitation parameters.

Ahmad Iftikhar, Hassan Adnan, Anjum Muneeb Ullah, Malik Sohail, Ali Tashfeen «Ambient Acoustic Energy Harvesting using Two Connected Resonators with Piezoelement for Wireless Distributed Sensor Network» Акустический журнал, 65, № 5, с. pp. 471-477 (2019)

In this article, an acoustic energy harvester (AEH) is conceptualized, designed, fabricated and tested. The developed AEH (DAEH) consists of two Helmholtz cavities (HCs) and a commercially available piezoelement. The HCs were fabricated from Teflon material using conventional machining operations. An indigenous test bench for in-lab characterization of DAEH has also been developed. Various experiments were performed to experimentally record the frequency response function, loading and power characteristics. Additionally, the in-lab and open-air characterization of the DAEH is also reported. Furthermore, the proposed prototype of DAEH is compared on the basis of various benchmarks with the prototypes available in the literature. The experimental results indicate a maximum power density of 32.7 μW/cm³ at 130 dB.

Maltsev N.E. «Numerical Implementation of Huygens Principle for Scattering from a Smooth Ideal Surface» Акустический журнал, 65, № 5, с. pp. 467-470 (2019)

In 1678 Huygens formulated a principle postulating that each point on a wave front acts as a point source emitting a spherical wave which travels with a local velocity. The field at a given point some time later is then the sum of the fields of each of these point sources. In this article a numerical method is presented for 2D problems of sound propagation and scattering, conforming that physical assumptions.

Laidoudi F., Boubenider F., Mebarki M., Medjili F., Bettine F. «Numerical Investigation of Quasi-Lamb Modes in c–Tilted ZnO/SiC Composite Membrane for High Performance Pressure Micro-Sensor» Акустический журнал, 65, № 3, с. pp. 253-262 (2019)

Using the finite element method, we have studied the Lamb modes characteristics propagation in c tilted ZnO/SiC thin film composite membrane. Phase velocity dispersion curves, electromechanical coupling factors and the mass loading effect on the fundamental quasi Lamb modes are theoretically investigated for different rotating angle (0], τ°, 90°), τ being the angle of rotation, and for different h_ZnO/λ values. To develop high performance pressure micro-sensor based on thin film piezoelectric ZnO on amorphous SiC (range 0.1 to 100 Pa) the anti-symmetric fundamental qA0 mode phase shift is studied for pressure sensing.

Laidoudi F., Boubenider F., Mebarki M., Medjili F., Bettine F. «Numerical Investigation of Quasi-Lamb Modes in c–Tilted ZnO/SiC Composite Membrane for High Performance Pressure Micro-Sensor» Акустический журнал, 65, № 3, с. pp. 253-262 (2019)

Using the finite element method, we have studied the Lamb modes characteristics propagation in c tilted ZnO/SiC thin film composite membrane. Phase velocity dispersion curves, electromechanical coupling factors and the mass loading effect on the fundamental quasi Lamb modes are theoretically investigated for different rotating angle (0], τ°, 90°), τ being the angle of rotation, and for different h_ZnO/λ values. To develop high performance pressure micro-sensor based on thin film piezoelectric ZnO on amorphous SiC (range 0.1 to 100 Pa) the anti-symmetric fundamental qA0 mode phase shift is studied for pressure sensing.

Mikhailova E.A., Mikhailova V.A. «Effect of vibrational transitions on the nonthermal charge transfer probability» Математическая физика и компьютерное моделирование (ранее Вестник Волгоградского государственного университета. Серия 1: Математика. Физика), 22, № 2, с. 76-85 (2019)

In the framework of the stochastic approach, the effect of transitions between the vibrational sublevels of products on the ultrafast dynamics of “hot” (non-thermal) electron transfer in donor – acceptor complexes dissolved in a polar medium has been investigated. An analytical expression has been obtained for the probability of electron transfer, which takes into account the transition between the vibrational states of products and the mutual influence of sinks. Quantitative estimates of the scale of the mutual influence of sinks on the probability of electron transfer are made.

Mikhailova E.A., Mikhailova V.A. «Effect of vibrational transitions on the nonthermal charge transfer probability» Математическая физика и компьютерное моделирование (ранее Вестник Волгоградского государственного университета. Серия 1: Математика. Физика), 22, № 2, с. 76-85 (2019)

In the framework of the stochastic approach, the effect of transitions between the vibrational sublevels of products on the ultrafast dynamics of “hot” (non-thermal) electron transfer in donor – acceptor complexes dissolved in a polar medium has been investigated. An analytical expression has been obtained for the probability of electron transfer, which takes into account the transition between the vibrational states of products and the mutual influence of sinks. Quantitative estimates of the scale of the mutual influence of sinks on the probability of electron transfer are made.

Milekhina O.N., Nechaev D.I., Supin A.Ya. «Frequency Range of Compression for Discrimination of Acoustic Signals with Complex Spectra» Акустический журнал, 65, № 1, с. pp. 96-102 (2019)

Psychophysical experiments on listeners with normal hearing were conducted to discriminate the rippled spectra of an acoustic signal against maskers with different positions of the spectral band relative to the signal band. As the signal level changed from 50 to 80 dB SPL, the on-frequency masker level changed by 29 dB, whereas the low-frequency masker level (the position of the center of the spectral band was from –1.25 to –1 octave relative to the signal) changed by 8.7–9.8 dB. These results are interpreted as 0.3 dB/dB compression of responses to the signal and no compression of the effect of low-frequency maskers. If the spectral bands of the signal and masker partially overlap, discrimination of the spectral structure occurs predominantly in the part of the spectrum that does not overlap the masker spectrum and is subjected to low-frequency masking that is not compressed.

Mukhin N.V., Kutia M.M. «Thiophene determination in liquid hydrocarbons by in-line acoustic measurements» Известия высших учебных заведений России. Радиоэлектроника, 22, № 4, с. 82-88 (2019)

Introduction. Petroleum is a complex mixture of hydrocarbons. Sulphur is the most common heteroatom in petroleum and petroleum products. Its content in oil can reach 14%. The determination of sulphur in oil and its removal is of great importance, since sulphur compounds adversely affect the quality of petroleum products and pollute the environment. Desulphurization of hydrocarbons is important in the processing of petroleum products, which needs in usage of accurate and simple methods for the sulphur-containing components determination. Most of developed methods are difficult to apply for flow online analysis, which can create difficulties in using them to monitor the content of sulphur-containing heteroatomic components in real time. Acoustic sensors are one of the possible solutions. In term of sensing of flammable liquids, the use of the acoustic methods is attractive since the analyte is not a part of an electrical measuring circuit and it is only acoustically coupled that prevents an occurrence of a spark. Objective. The purpose of the work is to study the possibilities of online flow analysis of sulphur-containing heteroatomic components using acoustic measurements. The challenge is the development of a resonator system integrated with the pipe.Materials and methods. Thiophene and oil fraction with the boundary boiling point of 100–140 °C were used to prepare the mixtures. Thiophene is a representative of sulphur-containing components, which may be included in the composition of petroleum and its derivatives. Experimental measuring equipment includes impedance analyzer, a developed sensor structure integrated with a liquid-filled pipe, a pump and a tank with a measured liquid. A theoretical analysis of sensor structure was carried out on the basis of numerical simulation using COMSOL Multiphysics software. Results. The sensor structure was designed as a combination of 2D and 1D pipe periodic arrangements to achieve high Q-factor of acoustic resonance in the flow system. The eigenmodes of the sensor structure with a liquid analyte were carried out. The characteristic of sensor structure is determined. The sensor shows good sensitivity to the thiophene content with high resolution in-line analysis. This result is achieved by limiting the energy losses of acoustic resonance in radiation along the pipe by creating a periodic structure. Conclusion. The study of acoustic properties of solutions prepared on the basis of thiophene and oil fraction with boundary boiling point 100–140°C was performed. It shows that methods based on acoustic spectroscopy make it possible to accurately determine the concentration of heteroatomic components in gasoline mixtures, since the presence of heteroatomic components leads to a change in mechanical properties of liquid hydrocarbons mixtures. Possible applications for developed acoustic sensor are flow analysis for monitoring the quality of oil products.

Mukhin N.V. «Микрофлюидный акустический метаматериал датчика на основе ПАВ» Известия высших учебных заведений России. Радиоэлектроника, 22, № 4, с. 75-81 (2019)

Introduction. Microacoustic sensors based on surface acoustic wave (SAW) devices allow the sensor integration into a wafer based microfluidic analytical platforms such as lab-on-a-chip. Currently exist various approaches of application of SAW devices for liquid properties analysis. But this sensors probe only a thin interfacial liquid layer. The motivation to develop the new SAW-based sensor is to overcome this limitation. The new sensor introduced here uses acoustic measurements, including surface acoustic waves (SAW) and acoustic methamaterial sensor approaches. The new sensor can become the starting point of a new class of microsensor. It measures volumetric properties of liquid analytes in a cavity, not interfacial properties to some artificial sensor surface as the majority of classical chemical and biochemical sensors. Objective. The purpose of the work is to find solutions to overcome SAW-based liquid sensors limitations and the developing of a new sensor that uses acoustic measurements and includes a SAW device and acoustic metamaterial. Materials and methods. A theoretical analysis of sensor structure was carried out on the basis of numerical simulation using COMSOL Multiphysics software. Lithium niobate (LiNbO3) 127.86° Y-cut with wave propagation in the X direction was chosen as a substrate material. Microfluidic structure was designed as a set of rectangular shape channels. A method for measuring volumetric properties of liquids, based on SAW based fluid sensor concept, comprising the steps of: (a) providing sensor structure with the key elements: a SAW resonator, a high-Q set of liquid-filled cavities and intermediate layer with artificial elastic properties between them; (b) measuring of resonance frequency shift, associated with the resonance in liquid-filled cavity, in the response of weakly coupled resonators of SAW resonator loaded by periodic microfluidic structure; (c) determination of volumetric properties of the fluid on the basis of a certain relationship between the speed of sound in liquid, the resonant frequency of the set of liquid-filled cavities, and the geometry design of the cavity.Results. The new sensor approach is introduced. The eigenmodes of the sensor structure with a liquid analyte are carried out. The characteristic of sensor structure is determined. The key elements of introduced microfluidic sensor are a SAW structure, an acoustic metamaterial with a periodic set of microfluidic channels. The SAW device acts as electromechanical transducer. It excites surface waves propagating in the X direction lengthwise the periodic structure and detects the acoustic load generated by the microfluidic structure resonator. The origin of the sensor signal is a small frequency change caused by small variations of acoustic properties of the analyte within the set of microfluidic channels. Conclusion. The principle of the new microacoustic sensor, which can become the basis for creating a new class of microfluidic sensors, is shown.