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Experiment activity is an essential part of science learning. Suling (flute), a traditional musical instrument from West Java, can be used as a learning media for sound wave concepts. Technology-based mobile can be used as an experimental tool is Phypox. This study aims to report using a combination of Suling and Phypox in experiment activities. The designed activity aims to engage students in critical thinking. The instrument for measuring critical thinking consists of five questions based on the critical thinking aspect: interpretation, analysis, evaluation, inference, and explanation. The study used a one-group pre-and post-test design on 32 8th-grade students at one of the junior high schools in West Java Province, Indonesia. The study procedure is a pre-test, discussion of Suling’s concepts, introduction to Phypox apps, experiment activity, presentation, and post-test. Data analysis uses the normalized gain to compare the pre-and post-test. Experiment activities help students to understand frequency, open organ pipes concepts, and investigate the speed of sound produced by Suling. The study found a significant change in the pre-and post-test scores of students after experimenting, so it could be interpreted that the experimental activities using Suling and Phypox affected critical-thinking students. [ABSTRACT FROM AUTHOR]

Abstract Tomato (Solanum lycopersicum L.) is one of the most consumed vegetables worldwide. The ripening of tomato is performed for its freshness and represented by color and gene expression. In our previous study, we performed molecular analyses on tomato ripening with and without sound-wave treatment. In the present study, we performed metabolomics analysis of ripening tomatoes with and without sound-wave treatment to expand our knowledge of tomato ripening. To achieve this goal, tomatoes at 7, 10, and 14 d of ripening were selected and analyzed via liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–MS (GC–MS). A total of 33 major metabolites, including 14 LC–MS- and 19 GC–MS-derived metabolites, were assigned based on variable importance projection and p values and subjected to statistical analysis. Apparent morphology and partial least squares–discriminant analysis were consistent with the general ripening process based on color. Moreover, metabolomics analysis showed similar experimental results to those of previous studies. The quantification of metabolites with LC–MS showed decreasing levels of adenosine, tryptophan, and phytosphingosine upon sound-wave treatment. In GC–MS analysis, 4-Aminobutanoic acid and aspartic acid were decreased upon sound-wave treatment. On the other way, the quantity of malic acid, citric acid, and sucrose was increased with the treatment. The findings of this study can assist in the application of sound-wave treatment for delaying ripening in tomatoes and improving their market value.

A theoretical study has been made of the reflection and refraction of a harmonic sound wave on the boundary "bubble liquid–porous medium saturated with bubble liquid." It has been established that in the case of incidence of such a wave on the indicated boundary at a certain angle, the total internal reflection of a transverse wave occurs. Conditions have been determined with which the reflection of the wave as that from a rigid wall occurs. [ABSTRACT FROM AUTHOR]

Plants are highly sensitive organisms and can indeed benefit from specific sound signals in multi-layered processes. Scientific evidences have shown the potential applications of sound wave treatment in plant biology. However, there are some limitations to sound wave treatment that must be overcome. We still do not understand how do plants initially perceive and recognize sound signals, which is very critical to maximize the effectiveness of the use of sound treatment from practical viewpoint. Proper setup of sound treatment equipment and detailed understanding and evaluation of the effects of selected frequencies and intensities along with sound exposure times are also very crucial during sound treatment. More experimental studies with different models need to be done in a multidisciplinary approach toward establishing suitable mechanism for sound treatment application in agriculture production. The aim of this paper is to provide an overview of findings associated with potential effects of audible sound waves including music on different biological, physiological and biochemical processes in plants. [ABSTRACT FROM AUTHOR]

The development of science and technology has positively impacted human life, which has now reached the age of electric voice commands. An intelligent home management system allows humans to operate their house's electrical gadgets, such as lighting, using simple voice commands, eliminating the need to move around to switch on or off equipment. When users of indoor lighting use sound waves to operate the system or turn on the lights, the sound sensor sends an input signal to the microcontroller, which is then processed with the microcontroller's output in the form of a voltage to turn on the load. The system will function when the FC-04 sound sensor receives sound input (sound code). The FC-04 sound sensor can only provide a digital output signal with a value of 1 and 0 in the form of a clap, which is then accumulated on Arduino with a value above 400 million by the program uploaded to be used as a 5-volt output to turn on/off the lights. This is because when turning on the lights from a certain distance, several factors can affect it, including setting the sound sensor's sensitivity and noise levels in the surrounding area.

Tomato (Solanum lycopersicum L.) is one of the most consumed vegetables worldwide. The ripening of tomato is performed for its freshness and represented by color and gene expression. In our previous study, we performed molecular analyses on tomato ripening with and without sound-wave treatment. In the present study, we performed metabolomics analysis of ripening tomatoes with and without sound-wave treatment to expand our knowledge of tomato ripening. To achieve this goal, tomatoes at 7, 10, and 14 d of ripening were selected and analyzed via liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–MS (GC–MS). A total of 33 major metabolites, including 14 LC–MS- and 19 GC–MS-derived metabolites, were assigned based on variable importance projection and p values and subjected to statistical analysis. Apparent morphology and partial least squares–discriminant analysis were consistent with the general ripening process based on color. Moreover, metabolomics analysis showed similar experimental results to those of previous studies. The quantification of metabolites with LC–MS showed decreasing levels of adenosine, tryptophan, and phytosphingosine upon sound-wave treatment. In GC–MS analysis, 4-Aminobutanoic acid and aspartic acid were decreased upon sound-wave treatment. On the other way, the quantity of malic acid, citric acid, and sucrose was increased with the treatment. The findings of this study can assist in the application of sound-wave treatment for delaying ripening in tomatoes and improving their market value. [ABSTRACT FROM AUTHOR]

In this paper, we propose an efficient sound propagation and remapping technique based on geometry to enhance immersive sound effects in virtual environments, and suggest a method to interactively represent sound by considering the altitude and slope of the terrain. The proposed technique can represent real-time patterns of sound such as waves and flows of sound, as well as diffraction that occur in a physical environment. Our approach involves identifying the position of obstacles from the sound source and calculating the new position of sound that has been refracted or diffracted due to the obstacles. Using a ray-tracing technique, we determine whether there is a collision between obstacles and sound, and calculate the reflected and refracted vectors due to the collision to predict the magnitude of sound that agents beyond the obstacles would hear. In this process, the number of reflected and refracted rays affects the magnitude of sound, allowing us to model sound attenuation based on the distance to the obstacle and the material of the obstacle. In this process, we control the magnitude of sound based on the altitude difference from the sound source and the gradient difference depending on the shape of the surrounding terrain. As a result, we efficiently and quickly represented diffraction patterns expressed in a physically-based approach, and demonstrated that the magnitude of sound diffuses naturally according to the deformed diffraction pattern as the obstacles move and rotate. Furthermore, we realistically represented the sound heard by the audience in terrains with altitude differences, and demonstrated that the magnitude of sound varies depending on the terrain.

Plants are highly sensitive organisms and can indeed benefit from specific sound signals in multi-layered processes. Scientific evidences have shown the potential applications of sound wave treatment in plant biology. However, there are some limitations to sound wave treatment that must be overcome. We still do not understand how do plants initially perceive and recognize sound signals, which is very critical to maximize the effectiveness of the use of sound treatment from practical viewpoint. Proper setup of sound treatment equipment and detailed understanding and evaluation of the effects of selected frequencies and intensities along with sound exposure times are also very crucial during sound treatment. More experimental studies with different models need to be done in a multidisciplinary approach toward establishing suitable mechanism for sound treatment application in agriculture production. The aim of this paper is to provide an overview of findings associated with potential effects of audible sound waves including music on different biological, physiological and biochemical processes in plants.

Elastography is of great interest in biomechanics and medical imaging due to its nondestructive capability of mapping elasticity of tissues. The elastography framework relies on external excitations which actuate deformation inside an object. The internal response is then acquired and analyzed to map the distribution of elastic moduli. In this paper, with no need of measuring any internal responses, an integrated elastography method is developed which only requires the transmitted responses of applied sound waves. During the process, the tomography image (e.g., CT or MRI) and the applied waves are integrated into a computational model. Following a procedure of inverse analysis, the elasticity of all phases in the object is reconstructed when the computational transmission of waves matches with the measured transmission. The numerical simulation on brain tissues and a demonstration on silicon rubber phantom are conducted to validate the proposed method. Both cases demonstrate that the integrated method successfully predicts the real elasticity of samples. The verification measurements on the phantom further show that the predicted elastic moduli agree well with the experimental results of uniaxial compression testing.

Elastography is of great interest in biomechanics and medical imaging due to its nondestructive capability of mapping elasticity of tissues. The elastography framework relies on external excitations which actuate deformation inside an object. The internal response is then acquired and analyzed to map the distribution of elastic moduli. In this paper, with no need of measuring any internal responses, an integrated elastography method is developed which only requires the transmitted responses of applied sound waves. During the process, the tomography image (e.g., CT or MRI) and the applied waves are integrated into a computational model. Following a procedure of inverse analysis, the elasticity of all phases in the object is reconstructed when the computational transmission of waves matches with the measured transmission. The numerical simulation on brain tissues and a demonstration on silicon rubber phantom are conducted to validate the proposed method. Both cases demonstrate that the integrated method successfully predicts the real elasticity of samples. The verification measurements on the phantom further show that the predicted elastic moduli agree well with the experimental results of uniaxial compression testing.

The selection of signal frequency in acoustic temperature measurement technology is the key to improve the accuracy of temperature measurement. In order to explore the optimal propagation frequency of low-frequency sound waves in loose coal, lignite, coking coal, and anthracite are used as the research objects. The acoustic loss of three coal samples under six particle sizes（0.9 mm to ＜3 mm, 3 mm to ＜5 mm, 5 mm to ＜7 mm, 7 mm to 10 mm, 9 mm to 10 mm and larger than 10 mm） by using the acoustic loss test system is tested. The experimental results show that the sound transmission loss of three coal samples presents a wave-like rising shape with the increase of the sound wave frequency. Compared with coal samples of other particle sizes, the sound transmission loss of coal samples in the range of 0.9 mm to ＜3 mm is the largest. As the particle size of coal samples increases, the sound transmission loss of coal samples continues to increase, and the sound wave frequency corresponding to the lowest point of sound transmission loss also increases. The degree of coal sample deterioration has no obvious regularity in the influence of sound transmission loss. The sample size is the main factor that affects the change of the sound transmission loss of the coal sample, and the sound waves mainly propagate along the gaps between the particle sizes of the loose coal. By comparing and analyzing the maximum and minimum values of sound transmission loss, there is a maximum value between 250 Hz to 600 Hz and 900 Hz to 1 600 Hz about the sound transmission loss of coal samples of different particle sizes, and the maximum sound transmission loss range is between 4.66 dB and 7.64 dB. By testing the sound transmission loss in the low-frequency sound waves of the mixture of three coal samples, it is determined that the optimal sound transmission frequency range in the loose coal is 600 Hz to 900 Hz.

The purpose of this study is to map the profile of high school students' conceptual understanding in physics subjects with the Doppler effect and sound intensity levels, and to show the causes of misconceptions in high school students from the results of the Certainty of Response Index (CRI) method applied. The research method is descriptive quantitative with data analysis techniques in the form of descriptive statistics. The data collection technique used is an ordinary multiple choice test instrument equipped with a confidence level scale using the model CRI (Certainty of Response Index). This confidence scale is used as data for understanding students' concepts in answering questions that are analyzed statistically. The research subjects were 66 high school students in class XI who were randomly selected and had received lessons on sound waves. The test results showed that there were misconceptions in each item with the largest percentage of 45.45% in item number 3 and the smallest 12.12% in item number 2. Other responses in the form of lucky guess and not knowing the concept were also found with varying percentages. The misconceptions encountered occurred in the use of signs for the speed of the observer and the speed of the source, the relationship between distance and number of sound sources at the level of sound intensity, and the relationship between sound magnitudes. The results of this concept understanding profile are expected to be information for teachers to be able to overcome students' misconceptions and arrange appropriate learning strategies during the learning process.

The reflection and transmission of harmonic waves at the interface between a bubbly liquid and a porous medium saturated with this liquid has been studied theoretically. The influence of the parameters of the system on the reflection and transmission coefficients through the interface between two media has been investigated. It has been found that for the interface between a bubbly liquid and a porous medium saturated with the bubbly liquid, there is a range of frequencies in which reflection occurs in the same way as from a free surface and back reflection as from a rigid wall. [ABSTRACT FROM AUTHOR]

Vegetable contamination by cadmium (Cd) is of great concern. Water spinach (Ipomoea aquatica) is a common leafy vegetable in many countries and has a strong ability to accumulate Cd. The work was conducted to study the effects of sound wave, water management, and their combination on Cd accumulation and growth of water spinach, using the following three experiments: a hydroponic trial with the treatment of a plant acoustic frequency technology (PAFT) generator in test sheds, a hydroponic trial with three music treatments (electronic music (EM), rock music (RM), and classical music (CM)) in artificial climate boxes, and a soil pot trial with treatments of PAFT and EM under non-flooded and flooded conditions. The results showed that the hydroponic treatments of PAFT and EM significantly reduced the Cd concentrations in roots and shoots (edible parts) of water spinach by 22.01–36.50% compared with the control, possibly due to sound waves decreasing the root tip number per unit area and increasing average root diameter, root surface area, and total root length. Sound wave treatments clearly enhanced water spinach biomass by 28.27–38.32% in the hydroponic experiments. In the soil experiment, the flooded treatment significantly reduced the Cd concentrations in roots and shoots by 43.75–63.75%, compared with the non-flooded treatment. The Cd decrease and the biomass increase were further driven by the PAFT supplement under the flooding condition, likely related to the alteration in root porosity, rates of radial oxygen loss, extractable soil Cd, soil Eh, and soil pH. Our results indicate that the co-application of plant acoustic frequency technology and flooded management may be an effective approach to reduce Cd accumulation in water spinach. [ABSTRACT FROM AUTHOR]

Preliminary observations show the limitations of teaching materials that have a relationship with spiritual aspects, especially the Qur'an, which is due to the limitations of teaching materials that contain these aspects. Required learning that stimulates students to generalize religious aspects and learn physics. Therefore, the purpose of this study is to describe the feasibility of physics teaching materials containing the Qur'an by using a generative model on sound wave material. This study aims to describe the validity, practicality, and effectiveness of the teaching materials developed. The research was conducted on 33 students at class XI MIPA 1 MAN 2 Model Banjarmasin using the ADDIE model. Data was taken from the validation results of teaching materials using validation sheet, lesson plan implementation using lesson plan implementation sheet, and students' learning outcomes at the pretest and post-test using learning outcomes tests. The results of this study were 1) the validity of the teaching materials was in the "valid" category with a value of 3.33, 2) the practicality of the teaching materials was in the "very practical" category with a value of 3.63, and 3) the effectiveness of the teaching material was in the "effective/moderate" category with a value of 0,44. This study concluded that physics teaching materials containing Al-Qur'an verses on sound wave materials using generative learning models are declared feasible to be used based on the validity, practicality, and effectiveness of the teaching materials. The implication of this research is the creation of teaching materials containing the Qur'an that are used in schools and creating student habits to link physics and the Qur'an.

Highlight Research • The mortality of lobster seeds by predators in the first year is 96.0-99.4% • It takes technology to catch seeds before being eaten by predators • Application of sound wave-based attractor technology to lobsters • Do lobsters have the ability to hear sound waves? • The lobster's sense of hearing begins to function from the puerulus stage Abstract Indonesia is a country that produces abundant lobster seeds (puerulus), however, there is a paradox, where natural mortality in the first year since entering the settlement phase can reach 96.0-99.4%. The use of lobster resources, especially in the puerulus stage, for cultivation, is very strategic. Therefore, it is necessary to improve puerulus fishing technology. In the capture fisheries sector, the use of the sense of hearing in fish resources has been carried out to increase catch productivity, by utilizing sound wave-based attractors' technology. For lobster resources, to what extent is this technology applicable? Underwater sound waves are a phenomenon of compression and expansion of a medium as sound energy passes through it. This aspect of the study is still new and very prospective. The purpose of this review article is to answer some basic questions: Can lobsters be able to hear sounds that come from their surroundings, since when do lobsters sense of hearing begin to function, and anatomically what kind of auditory organs are in lobsters. The results of the review conclude as follows: lobsters have senses that are able to perceive or listen to sound waves (sound) from their surrounding environment, this ability has been possessed by lobsters since they were in the postlarva or puerulus stage. Anatomically, the organs that act as the sense of hearing in lobsters are: receptors on the body surface, chordotonal organs and statocyst organs.

Repairing cracks in the concrete of a building is very important to ensure the safety of a nuclear power plant. However, repair work in areas with very strong radiation is very difficult. Many robots have been proposed to solve this problem. However, they cannot operate wirelessly and have problems such as being left as debris in the event of an accident. To solve the problem, this paper investigates the feasibility of sound-driven robots. We focused on Helmholtz resonance to achieve this goal. In this paper, Helmholtz resonators were adopted as the drive source of the actuator, and a new prototype was created by devising the arrangement. We also examined the physical characteristics of the developed prototype. Unlike conventional actuators, the proposed device can be moved remotely simply by irradiating sound from the outside. The advantage of using sound waves is that the robot can move without being affected by electric or magnetic fields. Through some experiments, it was confirmed that the developed actuator can be moved remotely with sound. [ABSTRACT FROM AUTHOR]

Fire is a natural disaster that can be caused by many different reasons. Recently, more environmentally friendly and innovative extinguishing methods have started to be tested, some of which are also used. For this purpose, a sound wave fire-extinguishing system was created and firefighting tests were performed. With the data obtained, as a result of 17,442 tests, a data set was created. In this study, five different machine learning methods were used by using the data set created. These are artificial neural network, k-nearest neighbor, random forest, stacking and deep neural network methods. Stacking method is an ensemble method created by using artificial neural network, k-nearest neighbor, random forest models together. Classification of extinction and non-extinction states of the flame was made with the models created with these methods. The accuracy of models in classification should be analyzed in detail in order to be used as a decision support system in the sound wave fire-extinguishing system. Hence, the classification processes were carried out through the 10-fold cross-validation method. As a result of these tests, the performance analysis of the models was carried out, and the results showed that the highest classification accuracy belongs to the stacking model with 97.06%. The classification accuracy was determined 96.58% in random forest method, 96.03% in artificial neural network model, 94.88% in deep neural network model and 92.62% in k-NN model. The performance of the methods was compared by analyzing the performance metrics of machine learning methods. Thanks to the decision support system to be obtained based on the results of the analyzes, the sound wave fire-extinguishing system can be used efficiently.

This study aimed to explore the effect of the sound wave and membrane inclination i.e., 45° and 90° (MI45 and MI90) on the performance of osmotic microbial fuel cell (OMFC). The vibrations were given by a sound intensity of 60–80 dB and 20–1000 Hz in an anode compartment for a period of 5–6 h per day. Membrane inclination was given to maximizing the effective surface area under a fixed plane without changing its volumetric capacity to enhance water flux. Membrane inclination increased the effective surface area up to 33.33%, therefore, water flux was increased by 10% by using 45° inclination. The OMFC produced maximum water flux, reverse salt flux and power density of 0.750 ± 0.02 and 0.666 ± 0.02 Lm-2h−1, 3.18 ± 0.02 and 3.10 ± 0.02 gm-2h−1, 35.22 ± 12 and 24.22 ± 08 mW.m−2 for MI45 and MI90 respectively with the effect of sound. The chemical oxygen demand (COD) removal was found 66.85 ± 1% and 59.51 ± 1% with and without the effect of sound. Therefore, sound reduced the OMFC start-up time by 2–3 days based on open-circuit voltage data and also increased the anaerobic degradation by 6–9%. Overall, sound stimulates bacterial growth for the degradation of organic matter, and membrane inclination gives a more effective surface area for water flux.

At present, the multiphase flow technology is applied increasingly in oil and gas mixed transportation system.However, the safety problems of multiphase pipeline are much more complicated than that of single-phase pipeline. Acousticsensing technology has the advantages of wide frequency range, long propagation distance and easy identification, and it isapplied to the two-phase flow pipeline with multiphase medium. Based on the variation of the maximum mean value and themaximum mean square value of the dynamic pressure signal before and after the leakage, the influence of the flow pattern, flow rate, leakage direction and leakage aperture on the leakage signal can be judged. Further, through theoretical analysis, the model of the relationship between the fluctuation amplitude of dynamic pressure and the gas-liquid flow during thestable flow of smooth stratified flow, wavy stratified flow and slug flow was established, which could be used to determinethe background noise amplitude fluctuation of steady flow under each flow pattern, laying a foundation for the realization ofacoustic leakage detection technology for gas-liquid two-phase flow pipeline.

Two problems of the monoharmonic sound wave transmission through a thin rectangular composite plate hinged in the opening of an absolutely stiff dividing wall were considered using the discrete layered damping model of a multilayer plate at small displacements and deformations, with account of the internal damping of layers according to the Kelvin–Voight model. In setting the first problem, it was assumed that the plate located between two semiinfinite spaces and a plane sound wave with a given amplitude value of the pressure is incident on it. In setting the second problem, it was considered that the plate is situated between two absolutely stiff barriers; one of them, owing to the harmonic vibration with a given displacement amplitude of the plate, forms an incident sound wave, while the other is stationary and coated by an energy-absorbing material with high damping properties. Behavior of the acoustic media was described by the classical wave equations based on the model of an ideal compressible fluid. Exact analytical solutions of the formulated problems were constructed. With their help, the sound insulation parameter of composite plate reinforced with carbon fiber textile was studied and the characteristics of its stress-strain state were investigated depending on the frequency of the incident sound wave. It was shown that the mechanics of the deformation of structural elements made of fiber-reinforced composites under high-frequency acoustic impact must be described by refined equations of motion, which have a high degree of accuracy and pithiness, because the stress-strain state formed in them are almost three-dimensional.

The relevance of the research follows from the need to assess the dynamic level of liquid in oil producing and water wells with the necessary frequency, which can be provided as one of the functions of an intelligent well. The aim of the research is to search for alternative methods for determining the liquid level in the annulus of wells without involving personnel in the well zone. Objects: oil producing wells equipped with pressure sensors, generators and receivers of acoustic waves and secondary instruments for transmitting information to the workplaces of the personnel of the enterprise. Methods: based on the well-known laws of physical hydrodynamics and methods of mathematical statistics. Results. The soundometric method for determining the dynamic liquid level in the annulus of a well has an error in measurements in existing oil wells due to the inconstancy of the composition of associated petroleum gas in time and in the depth of the tubing at a fixed point in time.

The echo reduction of an underwater vessel is one of the major concerns of its concealing problem. Recently, using scatterers in the doubly periodic distribution has attracted enormous interest. This is because of their relatively good performance and the ability to tune in the effective frequency range. In this study, a model of an acoustic echo reducing coating with internal scatterer cavities is considered. Subsequently, the major parameters that affected the acoustical performance of the layer, such as the size, the number and the location of cavities along with the thickness, for two types of spherical and cylindrical cavity geometries, were analyzed and presented. The results showed that in the layer, the larger the cavity size, the greater the echo reduction effect. Regarding the lattice constants, considering the smaller one, decays the echo reduction. However, will increase transmission loss. Also, the location of the cavity, if close to the wave entry plane, demonstrates a better echo reduction effect.

In order to deflect the radiated sound waves by an array of sound sources, temporal phase differences between the adjacent sound sources are necessary. Usually, the sound can be deflected by electronically providing the phase-shifted driving signal to sound sources comprising the array. In this study, we propose a new method for deflecting sound emitted from a linear array of sound sources whose driving frequency, amplitude, and phase characteristics are all consistent. Instead of directly changing the phase of the driving signal, the dynamic characteristics of the vibration systems installed in front of the emitter are adjusted to cause a physically phase-shifted response. Such an indirect phase difference caused by the vibrator array achieves the deflection of the interfered sound waves. Firstly, numerical calculations are performed by assuming different natural frequencies to the vibrators composing an array so that the radiated sound could be deflected at angles of θ = 20°, 30°, 40°, 50°, and 60°. It was found that the desired deflection angle could be obtained under all conditions. Secondly, experiments were conducted to verify the numerical predictions. Thin resin plates with different elastic moduli were manufactured that mimicked vibrators. We confirmed that the sound wave could be deflected for all deflection angles at the sound source frequency of 4 kHz.

The energy-velocity relation of a dark soliton is usually derived by its exact solution, which has been used to explain the kinetic motion of the dark soliton widely in many-body physical systems. We perform a variational method to re-derive the dispersion relation, with the consideration that the number of particles of the dark soliton could be conserved. The re-derived dispersion relation is completely different from that given by the exact dark soliton solution. The validity of these two dispersion relations is tested by observing the motion of the dark soliton when we drive impurity atoms that coupled with the soliton. The results suggest that the dispersion relation given by the exact solution usually works better than the one with particle number conservation. This motivates us to reveal that density waves (carrying particle transport) are generated during the acceleration process of a dark soliton, in addition to the previously known sound waves (only carrying energy transport). We further show that the density wave emissions of dark solitons can be inhibited by increasing the impurity atom number, which is trapped by the dark soliton through nonlinear coupling. The discussion is meaningful for investigating and understanding the kinetic motion of dark solitons in many different circumstances.

Fire, one of the most serious disasters threatening human life, is a chemical event that can destroy forests, buildings, and machinery within minutes. For this reason, there have been numerous methods developed to extinguish the fire. Within the scope of this study, a sound wave flame extinction system was developed in order to extinguish the flames at an early stage of the fire. The data used in the study were obtained as a result of experiments conducted with the developed system. The created dataset consists of data obtained from 17,442 experiments. It is aimed to classify the fuel type, flame size, decibel, frequency, airflow and distance features, and the extinction-non-extinction status of the flame through rule-based machine learning methods. In the study, rule-based machine learning methods, ANFIS (Adaptive-Network Based Fuzzy Inference Systems), CN2 Rule and DT (Decision Tree) were used. The methods of Box Plot, Scatter Plot and Correlation Analysis were utilized for statistical analysis of the data. As a result of the classifications, respectively, 94.5%, 99.91%, and 97.28% success were achieved with the ANFIS, CN2 Rule, and DT methods. As a result of the evaluations made by using Box Plot, Scatter Plot and Correlation Analysis.

Vegetable contamination by cadmium (Cd) is of great concern. Water spinach (Ipomoea aquatica) is a common leafy vegetable in many countries and has a strong ability to accumulate Cd. The work was conducted to study the effects of sound wave, water management, and their combination on Cd accumulation and growth of water spinach, using the following three experiments: a hydroponic trial with the treatment of a plant acoustic frequency technology (PAFT) generator in test sheds, a hydroponic trial with three music treatments (electronic music (EM), rock music (RM), and classical music (CM)) in artificial climate boxes, and a soil pot trial with treatments of PAFT and EM under non-flooded and flooded conditions. The results showed that the hydroponic treatments of PAFT and EM significantly reduced the Cd concentrations in roots and shoots (edible parts) of water spinach by 22.01–36.50% compared with the control, possibly due to sound waves decreasing the root tip number per unit area and increasing average root diameter, root surface area, and total root length. Sound wave treatments clearly enhanced water spinach biomass by 28.27–38.32% in the hydroponic experiments. In the soil experiment, the flooded treatment significantly reduced the Cd concentrations in roots and shoots by 43.75–63.75%, compared with the non-flooded treatment. The Cd decrease and the biomass increase were further driven by the PAFT supplement under the flooding condition, likely related to the alteration in root porosity, rates of radial oxygen loss, extractable soil Cd, soil Eh, and soil pH. Our results indicate that the co-application of plant acoustic frequency technology and flooded management may be an effective approach to reduce Cd accumulation in water spinach.

Abstract The detection of crack on materials is an important issue in industry. On the contrary to conventional methods, such as manual inspection, sensor detection, and image processing techniques, a new simple method to detect the crack is proposed with optical voice recorder based on digital holography in this paper. Holograms obtained with sound waves passing through the materials are recorded by using the digital holography technique. Temporal behavior of the sound wave passing through the material, which is obtained from these holograms, gives image of crack. In this article, cracks in various materials are determined by the proposed new method, and crack images obtained with this new system are presented.

Elastography is of great interest in biomechanics and medical imaging due to its nondestructive capability of mapping elasticity of tissues. The elastography framework relies on external excitations which actuate deformation inside an object. The internal response is then acquired and analyzed to map the distribution of elastic moduli. In this paper, with no need of measuring any internal responses, an integrated elastography method is developed which only requires the transmitted responses of applied sound waves. During the process, the tomography image (e.g., CT or MRI) and the applied waves are integrated into a computational model. Following a procedure of inverse analysis, the elasticity of all phases in the object is reconstructed when the computational transmission of waves matches with the measured transmission. The numerical simulation on brain tissues and a demonstration on silicon rubber phantom are conducted to validate the proposed method. Both cases demonstrate that the integrated method successfully predicts the real elasticity of samples. The verification measurements on the phantom further show that the predicted elastic moduli agree well with the experimental results of uniaxial compression testing.

Repairing cracks in the concrete of a building is very important to ensure the safety of a nuclear power plant. However, repair work in areas with very strong radiation is very difficult. Many robots have been proposed to solve this problem. However, they cannot operate wirelessly and have problems such as being left as debris in the event of an accident. To solve the problem, this paper investigates the feasibility of sound-driven robots. We focused on Helmholtz resonance to achieve this goal. In this paper, Helmholtz resonators were adopted as the drive source of the actuator, and a new prototype was created by devising the arrangement. We also examined the physical characteristics of the developed prototype. Unlike conventional actuators, the proposed device can be moved remotely simply by irradiating sound from the outside. The advantage of using sound waves is that the robot can move without being affected by electric or magnetic fields. Through some experiments, it was confirmed that the developed actuator can be moved remotely with sound.

This research that aimed to (1) produce instruments that were feasible to measure the ability to solve physics problems and nationalism, and (2) determine the quality of instruments that have been developed. This research was conducted through four stages, namely the design, preparation of tests, test trials, and preparation of valid instruments. The instruments developed are physics problem solving ability test instrument consists of 10 number essay questions and nationalism questionnaire consists of 35 items arranged in the form of a Likert scale. This research used qualitative and quantitative analysis provided by eight validators (experts, physics teachers, and peer reviewers), and empirical validation analysis. The content validation showed that the instruments developed were in the valid category with a validity value of 1.00 for each item in the two instruments developed. Empirical validation involved 250 high school students who were randomly selected. It was found that: (1) instruments developed in accordance with Partial Credit Model (PCM) in which all items developed were in the range of 0.77 to 1.33, (2) the instrument reliability was in the good category with in the range of 0.72 to 0.98 for both instruments, (3) the level of difficulty of problem solving ability instrument has good criteria in the range of - 0.88 to 1.81e. [ABSTRACT FROM AUTHOR]

The detection of crack on materials is an important issue in industry. On the contrary to conventional methods, such as manual inspection, sensor detection, and image processing techniques, a new simple method to detect the crack is proposed with optical voice recorder based on digital holography in this paper. Holograms obtained with sound waves passing through the materials are recorded by using the digital holography technique. Temporal behavior of the sound wave passing through the material, which is obtained from these holograms, gives image of crack. In this article, cracks in various materials are determined by the proposed new method, and crack images obtained with this new system are presented. [ABSTRACT FROM AUTHOR]

Sound waves affect plants at the biochemical, physical, and genetic levels. However, the mechanisms by which plants respond to sound waves are largely unknown. Therefore, the aim of this study was to examine the effect of sound waves on Arabidopsis thaliana growth. The results of the study showed that Arabidopsis seeds exposed to sound waves (100 and 100 + 9k Hz) for 15 h per day for 3 day had significantly longer root growth than that in the control group. The root length and cell number in the root apical meristem were significantly affected by sound waves. Furthermore, genes involved in cell division were upregulated in seedlings exposed to sound waves. Root development was affected by the concentration and activity of some phytohormones, including cytokinin and auxin. Analysis of the expression levels of genes regulating cytokinin and auxin biosynthesis and signaling showed that cytokinin and ethylene signaling genes were downregulated, while auxin signaling and biosynthesis genes were upregulated in Arabidopsis exposed to sound waves. Additionally, the cytokinin and auxin concentrations of the roots of Arabidopsis plants increased and decreased, respectively, after exposure to sound waves. Our findings suggest that sound waves are potential agricultural tools for improving crop growth performance.

Pulsed acoustic analyzers of chlorine in N2, air, and O2 are considered. The possibility of using these devices for technological process control in the chemical and related industries is demonstrated by mathematical modeling. [ABSTRACT FROM AUTHOR]

To calculate sound wave velocity, we performed the Hsu-Nielsen lead break experiment using the ANSYS/LS-DYNA finite element software. First, we identified the key problems in the finite element analysis, such as selecting the exciting force, dividing the grid density, and setting the calculation steps. Second, we established the finite element model of the sound wave transmission in a plate under the lead break simulation. Results revealed not only the transmission characteristics of the sound wave but also the simulation and calculation of the transmission velocity of the longitudinal and transverse waves through the time travel curve of the vibration velocity of the sound wave at various nodes. Finally, the Hsu-Nielsen lead break experiment was implemented. The results of the theoretical calculation and simulation analysis were consistent with the experimental results, thus demonstrating that the research method using the ANSYS/LS-DYNA software to simulate sound wave transmissions in acoustic emission experiments is feasible and effective.

The measurement of space charge density caused by the corona discharge around the overhead transmission line is a tough problem till nowadays. For this problem, a system for measuring the one-dimensional (1D) distribution of space charge density in a coaxial cylinder model under negative corona discharge in ambient air is developed. This system is a scale model which can provide research basis for actual overhead line measurement. The system consists of acoustic emission, space charge generation, and signal-receiving systems. The sound wave of an ultrasonic transducer is used to stimulate space charge generated by a small corona cage, and the applied voltage ranges from −34 kV to −38 kV. Charge vibration produces an electrical field (E-field) that can be measured with an E-field antenna. After obtaining the E-field signal, the adaptive noise cancellation method is adopted to eliminate noise interference so that the accuracy of charge density can be improved. The Townsend's analysis solution is used to calculate the theoretical value of space charge density. Experimental results are consistent with the simulation value and thus confirm the validity of the proposed adaptive noise cancellation method and sensing system. [ABSTRACT FROM AUTHOR]