Sound Waves Research Articles

Activities of Students During Learning Process in Mobile Learning Based on Android Package Kit

The current outbreak of COVID-19 has affected lives including closure of educational institutions. Based on Android Package Kit (APK), developed by authors, a learning multimedia-interactive can be accessed as a whole learning activity by the students, including the worksheet. The instrument used to collect data in this study is a worksheet that is integrated in the APK This worksheet is used to monitor students involvement and comprehension during mobile learning process. Students’ engagement of learning process on sound waves topic is measured manually based on the analysis of their written answers against the worksheet. In this study, 12 boys and 23 girls student of class XI answered the questions in worksheet to exceed passing score in sound waves concept during learning process. Based on the results of the study, it can be concluded that learning by using worksheets integrated into an APK can attract students’ interest to access it and increase student involvement in the learning process.
 Keywords: activities of students, learning process, mobile learning, android package Kit

Acoustic performance evaluation of railway boundary walls using a computational fluid dynamics-based simulation approach.

Railway noise has become a significant concern for trackside residents due to increased volume of high-speed passenger and freight train traffic. To address this, active measures, such as reducing noise at the source, and passive measures, such as installing noise barriers along the transmission path, are widely being used. In urban areas, railway boundary walls are constructed to prevent encroachments of railway lands and to avoid pedestrian trespassing of railway tracks. This study aims to evaluate the effectiveness of such a boundary wall for reducing noise and proposes an improved alternative through computational fluid dynamics (CFD) simulations. Various noise barriers with different geometry, shape, and surface materials were simulated and validated with the field conditions based on a rectangular wall of height 2.75 m. Noise attenuation was evaluated by measuring railway noise spectra at different positions, including 0.5 m in front and behind the barrier and at the facade of the residential area. The insertion loss based on field measurements for a rectangular barrier of height 2.75 m was observed to be 5.2 dBA. The simulation results indicated a positive correlation between barrier height and insertion loss, with a maximum attenuation of 17 dBA achieved with a barrier of height 6 m. The most effective noise barrier for reducing railway noise was a T-shaped barrier with a height of 6 m and a projection length of 2 m, with an insertion loss of 22 dBA. This study recommends constructing the barrier with soft materials on its surface to reflect and absorb sound waves effectively. These findings have potential implications for urban planners and policymakers in designing effective noise barriers in residential areas near railway lines.

Reflective vortex focusing for acoustic contact-free object rotation

The use of acoustic vortex waves with angular momentum is a promising means of transferring mechanical torque to an object without making any physical contact. However, the existing passive-conversion vortex lenses are unable to produce strong acoustic radiation torque. To address this issue, we propose a flat reflector sculpted by spiral grooves. It reflects and converts incident waves into vortex-focusing waves that generate radiation torque. Compared with a transmission-type lens, a reflection-type vortex focusing plate exhibits superior functionality in converging sound waves and creating a stronger circular intensity flow. In this work, we analyze the vortex-focusing sound by Rayleigh-Sommerfeld integral theory and boundary element simulation, confirmed by experiments. The number, depth and direction of spiral grooves determine the topological charge, focusing intensity and torque direction, respectively. We evaluate the local and total acoustic radiation forces and torques, acting on small and large fixed spherical targets in the vortex-focusing beam. As a result, spinning a centimeter-size origami pinwheel several times larger than the wavelength at 40 kHz is realized without direct contact, by utilizing the enhanced acoustic radiation torque converged by the reflector. This technology enables efficient convergence of acoustic waves and simultaneous contactless transfer of mechanical torque to an object, thereby presenting potential applications in sound energy harvesting and wireless power supplies.

Hydrostatic pressure response of semiconducting GaSb applying a semi-empirical approach

In addition to experimental investigations, semi-empirical approaches prove valuable for replicating experimental results and predicting material behavior under high-pressure conditions. This study investigates the variation of unit cell volume in cubic zinc blende Gallium antimonide (GaSb) up to the phase transition pressure, relying solely on structural parameters from literature measurements at ambient conditions. The research extends to inspect the impact of high pressure on various properties, including mass density, bulk modulus, bulk sound wave velocity, microhardness, first-order pressure derivative of the isothermal bulk modulus, Grüneisen parameter, and Debye temperature for the GaSb compound. The bulk modulus and microhardness show nearly linear increases with pressure, while sound wave velocity and Debye temperature exhibit nonlinear variations. The first-order pressure derivative of the bulk modulus and Grüneisen parameter gradually decreased in the material under study. Similar trends under pressure are found in literature for materials with different crystallographic structures. Additionally, the study predicts and analyzes extra physical parameters of GaSb, comparing them with existing literature data.

Sound reduction of side-branch resonators: An energy-based theoretical perspective

For over a century, side-branch resonators have served as effective acoustic filters, yet the explanation for their sound reduction capability has varied. This paper introduces a novel theory applicable to all types of side-branch resonators from an energy perspective and explains sound reduction as a consequence of acoustic energy redistribution. Our theory posits that a standing wave inside the resonator induces air vibration at the opening, which then acts as a secondary sound source, emitting acoustic energy predominantly in the form of kinetic energy. Due to the formation process of the standing wave, the sound wave generated by the resonator undergoes a phase shift relative to the original sound wave in the main pipe. Consequently, this generated sound wave, while matching the amplitude, possesses an opposite phase compared to the original noise wave within the main pipe. This antiphase relationship results in the cancellation of sound waves when they interact post-resonator in the main pipe. Our theory, grounded in an energy perspective, is derived from the principles of standing wave vibration and energy conservation.

Sound absorption performance of a micro-perforated plate sandwich structure based on selective laser melting

ABSTRACT This study proposes a sandwich structure of triply periodic minimal surface (TPMS) based on the theory of micro-perforated plates. This structure was processed using laser selective melting (SLM) with the acoustic-vibration theoretical model established through the acoustic-electrical analogy method. The theoretical model was verified by comparison with the experimental results, showing that the micro-perforated plate TPMS sandwich structure exhibited good sound absorption performance with the maximum sound absorption coefficients being higher than 0.8. The micro-perforated plate TPMS sandwich resonated when excited by sound waves. The change in the volume fraction affected the size of the cavity volume behind the micro-perforated plate, thereby affecting the resonance frequency. The increase in volume fraction decreased the volume of the cavity behind the structural plate, the sound absorption performance to increase, the resonance frequency to move towards high frequencies, and the sound absorption bandwidth to decrease. The resonance frequency was negatively correlated with the panel thickness. The increase in the panel thickness increased the maximum sound absorption coefficient and decreased the sound absorption bandwidth when the structure resonated. Also, high-order resonance frequencies appeared when the number of cell layers increased to a certain level.

Gradient index metamaterials for broadband underwater sound absorption

The underwater broadband anechoic coating is highly demanded in acoustic stealth for underwater vehicles. In this work, we propose a gradient index metamaterial for broadband underwater sound absorption, which is further experimentally validated under high pressure conditions. The gradient index metamaterial consisting of radius-varied cavities in rubber allows the sound waves to follow the objective trajectory in a broad band with impedance matching at the interface with water. The viscosity of the materials and the coupling effect among the gradient cavities contribute to broadband sound absorption. The performance of broadband sound absorption from 1 to 10 kHz is validated experimentally, which agrees well with the theoretical and numerical results. We further experimentally demonstrate the sound absorption performance with hydrostatic pressure up to 3 MPa and analyze the mechanism of the sound absorption deviation caused by high pressures. The proposed gradient index metamaterial provides a simple and efficient way to develop underwater broadband acoustic coatings.

Review of Automatic Water Tank Filling System Using Arduino

Abstract: This project revolves around an Arduino- based automatic water level controller and indicator, employing ultrasonic sensors for water level measurement. These sensors operate on the "echo" principle, wherein transmitted sound waves return after striking an obstacle. Utilizing this principle enables the calculation of travel time for both outgoing and returning waves, facilitating the determination of distance. This fundamental concept is integrated into the project design. The system activates the motor pump automatically when the water level is low, addressing the pressing issue of drinking water scarcity prevalent in India and other countries. The project aims to contribute to water conservation efforts, given the prevalent crisis. Many households in India use overhead tanks, resulting in water overflow and substantial wastage of both water and electricity. To combat this, the project introduces an automatic water level controller, eliminating the need for manual switching ON and OFF of the motor pump. The device continuously monitors the water level and triggers a relay, subsequently activating the motor pump. This automated process not only minimizes water and electricity wastage but also reduces the reliance on manual operation, thereby optimizing efficiency.

Broadband sound absorption using acoustic black holes with micro-perforated panels

In order to achieve broadband sound absorption, we propose a composite structure combining acoustic black holes (ABHs) and micro-perforated panels (MPPs). Here, we adopt both simulant and experimental methods to describe the sound transmission mechanism of the proposed composite ABH. This mechanism allows the ABH to have a sound absorption coefficient of over 0.8 in the range of 400–3200[Formula: see text]Hz and above 0.7 between 250[Formula: see text]Hz and 400[Formula: see text]Hz. The total length of the proposed ABH is 155[Formula: see text]mm, in which the thickness of the MPPs is 0.5[Formula: see text]mm, the pore size is 0.3[Formula: see text]mm and the porosity is 0.1 and 0.16, overcoming the length size and bandwidth limit for sound wave suppression in current ABHs. This work can further progress in elucidating the acoustic characteristics of ABH and open new avenues in ultra-broad-band sound wave control.

Experimental realization of fractal fretwork metasurface for sound anomalous modulation

Natural creatures and ancient cultures are full of potential sources to provide inspiration for applied sciences. Inspired by the fractal geometry in nature and the fretwork frame in ancient culture, here we design the acoustic metasurface to realize sound anomalous modulation, which manifests itself as an incident-dependent propagation behavior: sound wave propagating in the forward direction is allowed to transmit with high efficiency while in the backward direction is obviously suppressed. We quantitatively investigate the dependences of asymmetric transmission on the propagation direction, incident angle and operating frequency by calculating sound transmittance and energy contrast. This compact fractal fretwork metasurface for acoustic anomalous modulation would promote the development of integrated acoustic devices and expand versatile applications in acoustic communication and information encryption.

Vibro-acoustic response and sound transmission loss of sandwich plates with tunable Poisson's ratio core in a hygrothermal environment

In this study, vibro-acoustic response and sound transmission loss of sandwich plates with tunable Poisson's ratio (TPR) core in a hygrothermal environment are investigated. The sandwich plate is taken as a moderately thick plate and various plate theories are used to examine the vibroacoustic behavior. First, the equations of motion of a sandwich plate in the hygrothermal environment are derived based on Hamilton's principle. Then, the solution to free vibration for a simply supported sandwich plate is presented. Next, we obtain the sound power level (SPL) for the point harmonic force exerted on the surface of the sandwich plate using the Rayleigh integral and the sound transmission loss (STL) as the harmonic sound wave is incident on the plate surface. Finally, numerical examples are conducted and discussed. The effects of the core-to-thickness ratio, plate theories, parameters of the TPR core, hygrothermal environment, and incident elevation angle on the SPL and STL of the sandwich plate are analyzed. This study will contribute to the design and manufacturing of lightweight structures in the aviation industry.

Exploring Impact of the Ultrasound and Combined Treatments on Food Quality: A Comprehensive Review

As a response to the evolving consumer demand for healthier food choices, ultrasound application in food processing emerges as a sustainable and green solution with no residual effects. This method, known for its cost-efficiency and sustainability, holds significant promise in meeting the increasing need for high-quality, chemical-free, and natural-tasting convenience foods in the ever-changing landscape of the food industry. Ultrasound, leveraging mechanical sound waves, spans across various frequencies: power ultrasound (20–100 kHz), high-frequency ultrasound (100 kHz-1 MHz), and diagnostic ultrasound (1–500 MHz). This study focuses on investigating the impact of ultrasound and combined treatments on food quality, summarizing their diverse applications across different unit operations such as texture and rheology, emulsification and homogenization, crystal formation and modification, dehydration and drying, fermentation, filtration, preservation and shelf-life extension, flavor enhancement, color and appearance, antioxidant activity, enzyme activity and food digestibility, bioavailability and bio-accessibility, and specific food divisions including unprocessed, minimally processed, processed, and ultra-processed foods, as well as culinary ingredients. It delves into their effects on technological and functional aspects of food products, explores emerging trends, offers possible recommendations in ultrasound technology for the food industry, while also recognizing existing challenges and limitations associated with ultrasound and related technologies.

Identification of common stria vascularis cellular alteration in sensorineural hearing loss based on ScRNA-seq.

The stria vascularis (SV), located in the lateral wall of the cochlea, maintains cochlear fluid homeostasis and mechanoelectrical transduction (MET) activity required for sound wave conduction. The pathogenesis of a number of human inheritable deafness syndromes, age related hearing loss, drug-induced ototoxicity and noise-induced hearing loss results from the morphological changes and functional impairments in the development of the SV. In this study, we investigate the implications of intercellular communication within the SV in the pathogenesis of sensorineural hearing loss (SNHL). We aim to identify commonly regulated signaling pathways using publicly available single-cell transcriptomic sequencing (scRNA-seq) datasets. We analyzed scRNA-seq data, which was derived from studying the cochlear SV in mice with SNHL compared to normal adult mice. After quality control and filtering, we obtained the major cellular components of the mouse cochlear SV and integrated the data. Using Seurat's FindAllMarkers and FindMarkers packages, we searched for novel conservative genes and differential genes. We employed KEGG and GSEA to identify molecular pathways that are commonly altered among different types of SNHL. We utilized pySCENIC to discover new specific regulatory factors in SV subpopulation cells. With the help of CellChat, we identified changes in subpopulation cells showing similar trends across different SNHL types and their alterations in intercellular communication pathways. Through the analysis of the integrated data, we discovered new conserved genes to SV specific cells and identified common downregulated pathways in three types of SNHL. The enriched genes for these pathways showing similar trends are primarily associated with the Electron Transport Chain, related to mitochondrial energy metabolism. Using the CellChat package, we further found that there are shared pathways in the incoming signaling of specific intermediate cells in SNHL, and these pathways have common upstream regulatory transcription factor of Nfe2l2. Combining the results from pySCENIC and CellChat, we predicted the transcription factor Nfe2l2 as an upstream regulatory factor for multiple shared cellular pathways in IC. Additionally, it serves as an upstream factor for several genes within the Electron Transport Chain. Our bioinformatics analysis has revealed that downregulation of the mitochondrial electron transport chain have been observed in various conditions of SNHL. E2f1, Esrrb, Runx1, Yy1, and Gata2 could serve as novel important common TFs regulating the electron transport chain. Adm has emerged as a potential new marker gene for intermediate cells, while Itgb5 and Tesc show promise as potential new marker genes for marginal cells in the SV. These findings offer a new perspective on SV lesions in SNHL and provide additional theoretical evidence for the same drug treatment and prevention of different pathologies of SNHL.

Enhancing chicken breast meat quality through ultrasonication: Physicochemical, palatability, and amino acid profiles

Ultrasonication, a technology that employs high-frequency sound waves, has demonstrated potential for modifying the properties of various food items. However, the effect of ultrasonication on chicken meat, particularly concerning amino acid composition and flavor enhancement, has not been sufficiently investigated. The objective of this research was to bridge the gap in the literature by exploring the impact of various ultrasonic treatments at varying power levels (300, 500, and 800 W) and durations (10 and 30 min) on the physicochemical characteristics, texture, and amino acid profile of chicken breast meat, with a focus on improving its palatability and flavor. The results indicated that ultrasonication reduced the pH and cooking loss, as well as hardness and chewiness while simultaneously increasing lightness and yellowness values of chicken breast meat. Moreover, ultrasonication enhanced the amounts of essential amino acids, including glutamic acid, alanine, and glycine as well as the free amino acid content, which gives meat its savory and umami flavor. Furthermore, the results demonstrated significant changes in the texture and structure, as demonstrated by the scanning electron microscopy (SEM) images, and in chemical makeup of chicken breast meat, as indicated by the FTIR spectra. These modifications in the molecular and microstructural characteristics of meat, as induced by ultrasonication, may contribute to the enhancement of tenderness, juiciness, and overall palatability.

Design, Testing, Evaluation, and Implementation of an Arduino-based Mosquito-Repellent System

Aims: The primary objective of this research drive is to design, develop, and evaluate an Arduino-based mosquito-repellent system. This work underscores the importance of developing sustainable and eco-friendly solutions for mosquito control.
 Study Design: An Arduino microcontroller board is used, and an assembly language program is developed to repel mosquitoes from the surroundings. This system uses piezoelectric disks, LED lights, LCD monitor along with the Arduino board and produces ultrasonic sound to protect humans and the environment from mosquitoes.
 Place and Duration of Study: The research effort was steered by the authors in a group under the supervisor of a faculty member as a part of the course capstone project work of the Bachelor of Science in Engineering degree in Computer Science and Engineering at the American International University Bangladesh (AIUB), Dhaka, Bangladesh. The authors performed their research tasks at AIUB from May 2023 to January 2024.
 Methodology: The innovative mosquito-repellent system uses an Arduino Mega 2560 microcontroller to generate a cutting-edge solution to tackle the problem of mosquito infestations. The system can produce an electric signal that can emit mechanical ultrasound signals to be harnessed using a series-connected eight piezo-electric discs. To power up the system, it uses four Li-ion rechargeable batteries charged by using solar energy from the home solar system. Besides, it uses LEDs to indicate the status of the repellent system.
 Results: The generated ultrasonic signal is observed on the oscilloscope screen and its’ value is exhibited on the LCD screen to evaluate the system performance. Testing confirms that the system can drive away mosquitoes within its 3 m surroundings in 2-3 minutes. Besides, the system parameter and cost comparison show that this scheme suggests a worthwhile and sustainable result for making a mosquito-free environment.
 Conclusion: The development of a mosquito-repellent system using ultrasonic sound waves based on an Arduino microcontroller offers a sustainable and effective alternative to traditional methods of mosquito control. Since the system is chemical and health-hazard-free, it is eco-friendly and makes human life more comfortable. The system is portable and cost-effective, making it suitable for use in various settings.

A Multiscale Euler–Lagrange Model for High-Frequency Cavitation Noise Prediction

Abstract To simulate the microscale bubble distribution and its effect on high-frequency cavitation noise, we present a two-way transition and coupling Euler–Lagrange model. The model accounts for both cavity fission and environmental nucleation as sources of microscale bubbles, which are limited in the traditional mesh-based Euler models. We evaluate the model with the experimental data of truncated NACA0009 hydrofoil as well as the measured bubble size distributions, showing satisfactory results for velocity distribution, cavity patterns, and power law scalings of bubble size. Based on an acoustic analogy, we find that the model produces sound waves with smaller wavelengths and higher frequencies than the Euler model, which are mainly attributed to two factors: (1) microscale bubbles with high natural frequency and (2) intense multiple cavity collapse/rebound behavior. This model is promising for predicting the full-spectrum of cavitation noise.

Analysis of Science Content in the Jaran Kamput Tradition of the Lombok Community

Jaran Kamput is a tradition of the Lombok people that is still carried out today. The purpose of this research is to examine the science content that is relevant to the Jaran Kamput tradition. This descriptive qualitative research was conducted in Barejulat village, Jonggat sub-district, Central Lombok district. Data about the Jaran Kamput tradition were obtained through interviews and observations, then the data were analyzed descriptively to find science content relevant to the Jaran Kamput tradition. The results of this study indicate that the science content that is relevant to the Jaran Kamput tradition includes: the structure of plant tissue and its functions, natural and artificial additives, the balance of rigid bodies, and vibrations and sound waves. The results of this study are expected to be one of the alternatives for the enrichment of science materials for science teachers.

A robust approach for computing solutions of fractional-order two-dimensional Helmholtz equation

The Helmholtz equation plays a crucial role in the study of wave propagation, underwater acoustics, and the behavior of waves in the ocean environment. The Helmholtz equation is also used to describe propagation through ocean waves, such as sound waves or electromagnetic waves. This paper presents the Elzaki transform residual power series method (E\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbb {E}}$$\\end{document}T-RPSM) for the analytical treatment of fractional-order Helmholtz equation. To develop this scheme, we combine Elzaki transform (E\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbb {E}}$$\\end{document}T) with residual power series method (RPSM). The fractional derivatives are described in Caputo sense. The E\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbb {E}}$$\\end{document}T is capable of handling the fractional order and turning the problem into a recurrence form, which is the novelty of our paper. We implement RPSM in such a way that this recurrence relation generates the results in the form of an iterative series. Two numerical applications are considered to demonstrate the efficiency and authenticity of this scheme. The obtained series are determined very quickly and converge to the exact solution only after a few iterations. Graphical plots and absolute error are shown to observe the authenticity of this suggested approach.

Acoustic emission of kidney stones: a medical adaptation of statistical breakdown mechanisms

Kidney stones have a prevalence rate of > 10% in some countries. There has been a significant increase in surgery to treat kidney stones over the last 10 years, and it is crucial that such techniques are as effective as possible, while limiting complications. A selection of kidney stones with different chemical and structural properties were subjected to compression. Under compression, they emit acoustic signals called crackling noise. The variability of the crackling noise was surprisingly great comparing weddellite, cystine and uric acid stones. Two types of signals were found in all stones. At high energies of the emitted sound waves, we found avalanche behaviour, while all stones also showed signals of local, uncorrelated collapse. These two types of events are called ‘wild’ for avalanches and ‘mild’ for uncorrelated events. The key observation is that the crossover from mild to wild collapse events differs greatly between different stones. Weddellite showed brittle collapse, extremely low crossover energies (< 5 aJ) and wild avalanches over 6 orders of magnitude. In cystine and uric acid stones, the collapse was more complicated with a dominance of local “mild” breakings, although they all contained some stress-induced collective avalanches. Cystine stones had high crossover energies, typically ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} 750 aJ, and a narrow window over which they showed wild avalanches. Uric acid stones gave moderate values of crossover energies, ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} 200 aJ, and wild avalanche behaviour for ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} 3 orders of magnitude. Further research extended to all stone types, and measurement of stone responses to different lithotripsy strategies, will assist in optimisation of settings of the laser and other lithotripsy devices to insight fragmentation by targeting the ‘wild’ avalanche regime.

Removable and replaceable micro-mixing system with surface acoustic wave actuators

Abstract A micromixer based on a surface acoustic wave (SAW) has attracted a great deal of attention because of their ability to mix liquids and multiphase flows with very high mixing efficiency. However, since microfluidic channels cloud only be formed directly on the piezoelectric substrate in conventional SAW devices, contamination problems have arisen. In this study, by placing a solution that propagates sound waves between the microfluidic channel and the SAW excitation substrate, vibrations caused by SAWs are propagated into the micro-well to form a micro-mixing system. This system can provide a micromixer that is removable, replaceable, and contamination-free.