Frequency Sound Waves Research Articles

EXTH-39. A BENCH-TOP MODEL FOR THE OPTIMIZATION OF ULTRASOUND PARAMETERS FOR SONODYNAMIC THERAPY OF GLIOBLASTOMA

Abstract BACKGROUND In-vitro studies have demonstrated that low frequency sound waves can interact with hemo-porphyrin molecule to induce the production of reactive oxygen species. This biophysical phenomenon can induce tumour cell death in glioblastoma cells in-vitro. The purpose of this study was to evaluate the production of reactive oxygen species and expression of apoptotic markers in glioblastoma cells in response to varying total treatment time and ultrasound power using a bench-top focused ultrasound (FUS) device. METHODS U251 cells were exposed to 5-Aminolevulenic Acid (5-ALA) at varying concentrations for up to 24 hours. The time point with peak proto-porphyrin IX (PPIX) fluorescence was established using fluorescence activated cell sorting (FACS). A transducer utilized at 0.91MHz was placed on an inverted stage with the focus targeted to the bottom of a standard 96-well cell culture plate. Pressure wave delivery was confirmed using a hydrophone. GBM cells were treated with 5-ALA alone, FUS alone, or 5-ALA + FUS and the cells were incubated for 24 hours prior to measuring ROS induction and cell death. ROS was measured using FACS with the CellROX Green Kit for Oxidative Stress Detection and Annexin-V was measured using the Dead Cell Stain Kit. RESULTS Peak fluorescence intensity for PPIX in the U251 cell line was found to be induced through incubation with 5-ALA for 24 hours with a concentration 200mg/mL. The fluorescence intensity of PPIX was found to be 313% greater in the treated group compared to the control group. Peak ROS was observed using a 0.91MHz transducer frequency for a total time of 120s with 6W average power. ROS was 61% and 66% greater in the SDT group compared to the FUS and 5-ALA group respectively. CONCLUSION Using this bench-top set up we successfully induced ROS and apoptosis in U251 cells. Establishing a reliable in-vitro model will allow us to further investigate the effects of other sonication parameters such as burst length.

Wall-applicable metamaterial: mitigating resonance dip for enhanced sound transmission loss

In recent years, there has been a significant advancement in thermal insulation technology, allowing for the implementation of energy-efficient solutions in existing buildings while preserving their architectural and cultural significance. This recognition has led to the widespread adoption of External Thermal Insulation Composite Systems (ETICS). However, this brings the common challenge in acoustic engineering, the resonance dip, into the spotlight. When the frequency of an incident sound wave coincides with a mass-spring-mass resonance of the thermally insulated wall, the sound insulation drop occurs, possibly resulting in a reduction in transmission losses. This study introduces a wall-applicable design of Plate-type Acoustic Metamaterial (PAM) to effectively enhance sound transmission loss. We investigated in development a transfer matrix method combined with the effective mass density of PAM to model the ideal metamaterial wall and further compared it with the results based on mass-law methods. Design strategies to construct the ideal bandgap were developed by analyzing dispersion curves.

Calibration-free temperature monitoring of pulverized coal powder based on the dual-mode acoustic tomography

Accurate temperature measurement of the pulverized coal powder is crucial in detecting and preventing coal spontaneous combustion. Compared to other temperature measurement techniques, acoustic tomography using low frequency sound waves has the advantage of high penetration ability for non-intrusive temperature measurement inside the pulverized coal powder. Additionally, by employing an array of acoustic transducers mounted around the coal powder, the entire sensing area can be covered, enabling a comprehensive temperature distribution analysis through tomographic reconstructions. However, the main drawback of the acoustic temperature measurement is the model complexity in describing the dependence of acoustic sound speed on temperature in the porous pulverized coal powder. Accurate calibration is required to determine the model parameters for temperature retrieval, however, which is difficult for in situ industrial application. To solve this problem, we proposed a calibration-free temperature monitoring method based on the dual-mode acoustic tomography for pulverized coal. The three-parameter JCAL model is used to characterize the acoustic propagation in coal powder. The temperature and micro-structure parameters can be jointly retrieved from the reconstructed sound slowness and attenuation distributions at different frequencies. The feasibility and effectiveness of the proposed method are validated in the simulation study. Results show that the dual-mode acoustic tomography can provide calibration-free simplicity for pulverized coal temperature measurement, which has a great potential for industrial applications.

Frequency band optimization of cavity-type metamaterials by acoustic split-frequency multiplexing

This paper reports an experimental study on a cavity-type metamaterial for broadband sound absorption to break the one-to-one correspondence between back cavity and absorption peak. An acoustic valve composed of a thin plate and a concentrated mass was proposed to pass and block specific frequency sound waves. The results indicate that under the action of the acoustic valve, the unit cell of the metamaterial can obtain more absorption peaks than the number of physical back cavities. Finite element simulation shows that this mechanism can be attributed to acoustic split-frequency multiplexing in the back cavity. Specific parameters for the unit cell are optimized based on genetic algorithms. The consistent finite element simulation and experimental results indicate that the metamaterial with the acoustic valve can achieve efficient absorption performance at 150–550 Hz with a thickness-to-wavelength ratio of 1/28. This study provides valuable design strategies for cavity-type metamaterials to achieve broadband sound absorption.

Experimental research on dynamic response characteristics of lean premixed flame excited by acoustic standing wave

The compact combustor holds great potential in the aerospace field. However, it faces challenges in terms of interaction between acoustic waves and flames, which affects combustion efficiency and intensity. In this study, the dynamic response of lean premixed flames under the excitation of a transverse standing wave acoustic field with different frequencies and amplitudes. The results indicate that the flame's response frequency is consistent with the excitation frequency. Decreasing the sound wave frequency and increasing the sound amplitude both lead to an increase in flame area oscillation, thereby enhancing the heat release rate. However, excessively high sound pressure values can enhance fuel diffusion, resulting in a reduction in flame area or even local flame extinction, which significantly decreases flame intensity. This research provides valuable insights into the behavior of lean premixed flames under acoustic excitation, contributing to the optimization of combustion processes and improvement of efficiency and performance in compact combustors.

Classifying Liver Fibrosis through the Utilization of Transfer Learning and FCNET Classifiers

Abdominal Radiology is used for monitoring patients with liver diseases and to measure severity of liver fibrosis by using Ultrasound (US) images which is obtained by scanning. Scanning uses high frequency sound waves to take images of the affected human organs. Since liver is situated deep into the body the signal get weaker each time it passes through other organs which makes it difficult for diagnosis to overcome this difficult transfer learning technique is proposed in this system. The first step is to remove unwanted disturbances from the US images which is accomplished by pre-processing steps. To ensure the quality of the input images they undergo resizing of resolution, adjusting variations in brightness and contrast. The goal of pre-processing technique is to enhance the quality, uniformity, and relevance of the input images, making them suitable for feature extraction and subsequent classification of liver fibrosis stages. The next step is to apply the Expectation Maximum (EM) algorithm based on Region of Interest (ROI), which is a clustering technique used for image segmentation. The EM algorithm iteratively assigns pixels to different clusters based on their intensities and probabilistic models, aiming to identify distinct regions. The feature extraction process is carried out by Fully Connected Convolutional Neural Network (FCNET) models which enable extracting high level representations from original images and transfer learning classification is used for classification of fibrosis stages with improved accuracy.

Acoustic Target Strength of Thornfish (Terapon jarbua) Based on the Kirchhoff-Ray Mode Model

Thornfish (Terapon jarbua) is a significantly commercial species inhabiting the shallow coastal waters of the Indo-Pacific Ocean. To achieve effective underwater acoustic (UWA) monitoring on the abundance and population dynamics of this species, the comprehensive target strength (TS) characteristics should be investigated and understood. In this study, the Kirchhoff-ray mode (KRM) model was adopted to evaluate and analyze the acoustic TS of T. jarbua and its variations with the sound wave frequency, pitch angle distributions as well as morphological characteristics in the South China Sea. A total of 19 samples were captured and evaluated at four types of frequencies of 38 kHz, 70 kHz, 120 kHz, and 200 kHz. The results demonstrated that the TS of T. jarbua varied with the pitch angle shifts, and the number of secondary TS peaks increased as the increasing frequency accordingly. Two classic pitch angle distributions that included N[−5°, 15°] and N[0°, 10°] were adopted to calculate the average TS of T. jarbua. The fitted TS-L regression formulations and the standard b20 form equations were determined at different pitch angle distributions as well as frequencies. These results could support the accurate and reliable UWA abundance estimation in the South China Sea to facilitate a better understanding of the abundance and population dynamics of T. jarbua.

Numerical prediction of the whistling potentiality of a turbulent channel flow with corrugated walls

This study explores the turbulent flow-induced whistling phenomena in a channel with corrugated wall surfaces, which is crucial for mitigating the acoustic fatigue problem in the aerospace field. By solving a compressible linearized Navier–Stokes equation in the frequency domain, the interference between the turbulent flow field along the corrugated wall and the incident acoustic field is studied, including the acoustic wave scattering phenomenon caused by turbulence and the fluid perturbation induced by acoustic waves. In conjunction with this, the acoustic two-ports method is utilized to investigate the transfer-function model and predict the whistling potentiality of the turbulent flow along corrugated walls. Experimental validations through the literature results confirm the numerical accuracy of this aeroacoustic simulation strategy. Subsequently, the investigation extends to different cavity configurations with different cavity profiles and numbers, and the two-port scattering matrix is applied to quantify the acoustic transmission and damping coefficients caused by the background flow field and turbulent eddy viscosity. The acoustic power conversion mechanism between the turbulent flow field and the incident acoustic field is established, allowing for quick prediction and effective analysis of the generation frequency range of the whistling phenomenon. Furthermore, the modulation effect of sound waves on the fluid is studied by analyzing the response of the incident sound wave frequency to the phase interference momentum and shear layer of different configurations of corrugated cavities. The results show that compared with the right-edge configuration, the rounded-edge configuration produces whistling at a lower frequency due to the turbulence effect, and the number of cavities adjusts the intensity, not the frequency, of the sound power generated. In addition, the oscillation of the shear layer caused by sound waves is related to the cavity configuration and the sound wave frequency.

Pulsed Vibro-Acoustic Analysis Technique for Monitoring Bone Health in Preterm Infants: A Pilot Study.

Despite advances in neonatal care, metabolic bone disease of prematurity (MBDP) remains a common problem in preterm infants. The development of non-invasive and affordable diagnostic approaches can be highly beneficial in the diagnosis and management of preterm infants at risk of MBDP. In this study, we present an ultrasound method called pulsed vibro-acoustic analysis to investigate the progression of bone mineralization in infants over time versus weight and postmenstrual age. The proposed pulsed vibro-acoustic analysis method is used to evaluate the vibrational characteristics of the bone. This method uses the acoustic radiation force of ultrasound to vibrate the bone. The generated acoustic waves are detected using a hydrophone placed on the skin over the tibia. The frequency of vibration and the speeds of received acoustic waves have information regarding the material property of the bone. We examined the feasibility of this method through an in vivo study consisting of 25 preterm and 10 full term infants. The pulsed vibro-acoustic data were acquired longitudinally in preterm infants with multiple visits and at a single visit in full term infants. Speed of sound and mean peak frequency of slow and fast sound waves recorded by hydrophone were used to analyze bone mineralization progress. Linear mixed model was used for statistical analysis in characterizing the mineralization progress in preterm infants compared to data from full term subjects. Significance changes in wave parameters (speed of sound and mean peak frequency) with respect to the postmenstrual age and weight in preterm infants were observed with p-values less than 0.05. Statistical significances in speed of sound measurement for both fast and slow waves were observed between preterm and full term infants, with p-values of <0.01 and 0.02, respectively. The results of this pilot study indicate the potential use of vibro-acoustic analysis for monitoring the progression of bone mineralization in preterm infants.

Ultrasonic Assisted Three Component Synthesis of 3-Cyano-pyridine-2(1H)-ones

The requirements of sustainability and the green chemistry principles have prompted organic chemistry researchers to come up with novel methods for the synthesis of organic compounds that require minimum energy consumption and pose lesser environment harm. Ultrasonication of reaction mixtures is one such methodology. High frequency sound waves are known to emit energy that is utilized in product generation. Attempts were made to synthesize 2-pyridone derivatives using ultrasonication assisted method of synthesizing 3-cyano-pyridine-2(1H)-one starting from a three component one pot reaction. The reaction between cyanoacetamide, aromatic ketones and substituted aromatic aldehydes in the presence of NaOH as base yielded 4,6-diaryl-2-oxo-1,2-dihydropyridine-3-carbonitrile derivatives as a result of one-pot multicomponent reaction. The synthesized 4,6-diaryl-2-oxo-1,2-dihydropyridine-3-carbonitrile derivatives were characterized by 1H NMR, 13C NMR, HRMS and FTIR spectra. Ultrasonication has been found to significantly reduce reaction time, enhance reaction rate and yield compared to conventional heating methods.

High-order Bragg forward scattering and frequency shift of low-frequency underwater acoustic field by moving rough sea surface

Acoustic scattering modulation caused by an undulating sea surface on the space–time dimension seriously affects underwater detection and target recognition. Herein, underwater acoustic scattering modulation from a moving rough sea surface is studied based on integral equation and parabolic equation. And with the principles of grating and constructive interference, the mechanism of this acoustic scattering modulation is explained. The periodicity of the interference of moving rough sea surface will lead to the interference of the scattering field at a series of discrete angles, which will form comb-like and frequency-shift characteristics on the intensity and the frequency spectrum of the acoustic scattering field, respectively, which is a high-order Bragg scattering phenomenon. Unlike the conventional Doppler effect, the frequency shifts of the Bragg scattering phenomenon are multiples of the undulating sea surface frequency and are independent of the incident sound wave frequency. Therefore, even if a low-frequency underwater acoustic field is incident, it will produce obvious frequency shifts. Moreover, under the action of ideal sinusoidal waves, swells, fully grown wind waves, unsteady wind waves, or mixed waves, different moving rough sea surfaces create different acoustic scattering processes and possess different frequency shift characteristics. For the swell wave, which tends to be a single harmonic wave, the moving rough sea surface produces more obvious high-order scattering and frequency shifts. The same phenomena are observed on the sea surface under fully grown wind waves, however, the frequency shift slightly offsets the multiple peak frequencies of the wind wave spectrum. Comparing with the swell and fully-grown wind waves, the acoustic scattering and frequency shift are not obvious for the sea surface under unsteady wind waves.

Acoustic Wave Based Forest Fire Extinguisher and Detection Using Machine Learning

Worldwide, forest fires are a serious hazard to people, property, and the environment, needing creative approaches to early detection and prompt control. In order to establish an intelligent forest fire control system, this research introduces a cutting-edge methodology that blends conventional fire detection techniques with machine learning and cutting-edge technology. To find fires in a forest, we use flame sensors. The flame sensor informs a microcontroller when a fire is found. We offer a revolutionary form of fire suppression using Sonic Fire Extinguisher technology, which puts out flames by emitting high-frequency sound waves, as opposed to traditional fire suppression methods that use water or carbon dioxide. This strategy offers a safer and more environmentally friendly fire suppression technique. The technology incorporates machine learning to improve the speed and accuracy of fire detection. A SD card for sound file storage is included with the ARDUINO UNO microcontroller. In addition, the microcontroller is wired up with an amplifier and speaker. The microcontroller uses machine learning techniques to analyses the characteristics of the fire, such as size and intensity, and chooses the best sound wave frequency for suppression when the flame sensor detects a fire. This device can put out fires more effectively than conventional techniques and can adjust to various fire circumstances. The device can tailor the produced sound waves for effective fire suppression by fusing real-time data from the flame sensor with machine learning insights. This novel strategy improves the safety from forest fires while simultaneously minimizing the negative ecological effects of fire management activities. A promising approach to protecting priceless natural resources, people's lives, and property from the destructive impacts of forest fires is the combination of machine learning and Sonic Fire Extinguisher technology. This research Endeavour marks a significant advancement in the practice of finding fires and extinguishment, allowing a more environmentally responsible and sustainable method of managing forest fires.

Nonlinear analysis of sound transmission loss through cylindrical shell considering companion modes

This paper investigates the nonlinear vibro-acoustic performance of simply supported cylindrical shell under oblique incident plane sound wave including companion modes participation. The cylindrical shell equation of motion is obtained employing Donnell’s nonlinear shallow shell theory. The Galerkin method is applied to the equations of motion in order to obtain the system of nonlinear nonhomogeneous second order ordinary differential equations. The considered mode shapes are two asymmetric driven and companion modes and one axisymmetric mode. Multiple Scales Method is used to determine the response of resultant nonlinear differential equations. Next, the effects of incident sound characteristics on the transmission loss factor are studied. According to the results, effect of companion mode on the transmission loss (TL) through the shell can be seen only in high frequency of the incident sound wave. In addition, at high incident angle of acoustic wave, the companion mode effect on the TL of the system is very small.

Design and Research of a Sound-to-RGB Smart Acoustic Device

This paper presents a device that converts sound wave frequencies into colors to assist people with hearing problems in solving accessibility and communication problems in the hearing-impaired community. The device uses a precise mathematical apparatus and carefully selected hardware to achieve accurate conversion of sound to color, supported by specialized automatic processing software suitable for standardization. Experimental evaluation shows excellent performance for frequencies below 1000 Hz, although limitations are encountered at higher frequencies, requiring further investigation into advanced noise filtering and hardware optimization. The device shows promise for various applications, including education, art, and therapy. The study acknowledges its limitations and suggests future research to generalize the models for converting sound frequencies to color and improving usability for a broader range of hearing impairments. Feedback from the hearing-impaired community will play a critical role in further developing the device for practical use. Overall, this innovative device for converting sound to color represents a significant step toward improving accessibility and communication for people with hearing challenges. Continued research offers the potential to overcome challenges and extend the benefits of the device to a variety of areas, ultimately improving the quality of life for people with hearing impairments.

Agglomeration of oil droplets assisted by low-frequency sonic pretreatment

The metalworking process in industrial buildings produces small droplets of oil. The efficient purification of small oil droplets can protect the built environment and human health. Purifier performance is generally related to particle size, and increasing the particle size by pretreatment significantly improves purification efficiency. Acoustic agglomeration is a widely recognized technique for increasing dust particle size. In this study, the agglomeration efficiency (decrease in the number concentration) of oil droplets with a particle size of <5 μm under a sound wave was investigated. The operating parameters studied included sound wave frequency (1000–4000 Hz), waveform (sine, square, and triangular waves), sound pressure level (130–145 dB), and oil droplet residence time (2.5–4 s). The results show that the agglomeration efficiency peaks with frequency and increases linearly with the sound pressure level, first increasing sharply and then leveling off with residence time. The following were the optimum parameters:1800 Hz sine wave, 145 dB, and residence time of 3 s. Under these operating conditions, the agglomeration efficiency is 9.9%. The enhancement of acoustic agglomeration on purification by a wire mesh filter was verified, and it was shown that the purification efficiency of a wire mesh filter for 0.3–5 μm oil droplets increased by over 20%.

Acoustic injection method based on weak echo signals for leak detection and localization in gas pipelines

Underground gas pipelines are facing health and safety issues due to the material corrosion and equipment aging. Conventional acoustic methods may fail to detect and localize leaks in low and medium pressure gas pipelines because the sound of gas escaping from a leak source is usually too weak to be detected. In this paper, an active acoustic injection method is presented to stimulate specific frequency sound waves into the pipeline for leak detection based on weak echoes from the leak location. Further analysis is conducted on the relationships between the reflection coefficient and the size of the leak hole, the pipe diameter, the wall thickness of the pipe and the sound frequency. A signal reconstruction method is subsequently proposed to effectively detect and localize the echo signals. Finally, some experiments are carried out in a specially constructed gas pipe. Field test results indicate that a leak localization accuracy of 0.1 m can be achieved by the proposed method, which may be beneficial to practical leakage detection in gas pipelines.

Detection of underwater low frequency sound wave based on SiO2 optical waveguide resonator

Detection of underwater low frequency sound wave based on SiO2 optical waveguide resonator

Fabrication, sound absorption simulation and performance optimization of multi‐layer gradient fiber‐based composites

AbstractNoise reduction with materials of finite thickness has been a hot research topic. In this study, multi‐layer gradient fiber‐based composites integrating porous, resonant and damping structures were prepared for efficient sound absorption. Here, the effects of composite structure, fiber‐based thickness and micro‐perforated membrane fabric (MPMF) structure on the sound absorption of the composites were investigated. From the results, the sound absorption band of the composite can be effectively tuned by adjusting the structure of the MPMF or the thickness of the fiber‐based. In addition, the established acoustic model can accurately predict the sound absorption performance of the structure. It is worth mentioning that the gradient structure optimized by the algorithm exhibits broadband sound absorption (noise reduction coefficient of 0.42) and thin feature (thickness of 0.9 cm). Moreover, the medium and low frequency sound waves can be propagated and absorbed more easily by optimizing the structure of the composite. This work provides a reference for the preparation of multi‐layer gradient sound‐absorbing structures and the design of acoustic products in a specific frequency range.

Comparative GC-MS Analysis of Phytochemicals from Clitorea ternatea L. (White Flower Variety) Leaves Treated with Planetary Sounds (Planet Earth and Planet Jupiter) and Estimation of Bioactive Compounds

The butterfly pea (Clitoria ternatea L.) is a plant with various potential health benefits due to the presence of many bioactive compounds. The leaves contain triterpenoids, flavonoids, glycosides, and alkaloids. In the present experimental work, the leave extracts treated with planetary sound (Sound of Earth and Sound of Jupiter) classified as Medium-low frequency sound waves (200 Hz to 1 KHz), in methanol were checked for bioactive components through GC-MS and the third set was kept as control. Different bioactive compounds identified, were further estimated by using Lupeol (Merck, India) as an external standard. In compounds common among plants treated with Earth’s sound and control, 3-O-Methyl-d-glucose from plants treated with Earth’s sound was highest at 1.20 PPM. Compounds common among plants treated with Jupiter’s sound and control, 3-Hexenal from plants treated with Jupiter’s sound was found to be highest with 1.87 PPM, Similarly, compounds common among plant’s treated with Earth’s sound and Jupiter’s sound, Gamma sitosterol from leaves of plants treated with Earth’s sound was found to have highest value i.e, 1.27 PPM. Compounds that were common for all the three groups, plants treated with Earth’s sound was found to have increased Squalene with 1.23 PPM. A general trend of phytochemicals from plants treated with planet Earth’s sound had an elevated value. This suggests that the treatment of planet Earth’s sound has tremendous impact on the production of secondary metabolites in the referred species.

ANALISIS PERBANDINGAN FREKUENSI GELOMBANG BUNYI DENGAN TANGGA NADA PADA ALAT MUSIK MENGGUNAKAN APLIKASI PHYPOX

This research is an experiment to compare the frequency of sound waves generated from scales on wind instruments using the Phypox application on a smartphone. The data obtained from the research that has been done is the frequency of each scale on wind instruments like the flute and piano. The method used is descriptive-quantitative. Based on the data that has been obtained, it can be seen that of the five sets of frequency value data, four of them have relatively the same number of values, and the results of the data obtained in F1 have different values. It should be noted that the data were not collected at the same time and under the same conditions. This allows for differences in the results of the frequency values obtained. The difference in frequency values is caused by several factors, including the researchers' ability to produce sound vibrations, room temperature, and room silence.