@article{ author = {BahreiniMotlagh, M. and Roozbahani, R. and Eftekhari, M. and KardanMoghadam, H. and KavousiHeydari, A.R.}, title = {Design, manufacture and the evaluation of Fluvial Acoustic Tomography System (FATS)}, abstract ={Underwater Acoustic Tomography (AT) system transmits acoustic waves into the water. The AT systems continuously measure the physical characteristics of the flow in rivers, seas and the oceans. The AT systems are synchronized via a GPS clock connectied to the satellites. Hence, the systems transmit the acoustic waves at the same time. The systems record the arrival time of acoustic waves. After analyzing the received signals, the flow characteristics would be estimated. In the present study, design, manufacture and performance of an AT system are investigated in the Kousar Channel, Malek-Ashtar University of Technology. Two Fluvial Acoustic Tomography Systems (FATS) were deployed on both sides of the channel. The horizontal distance between two systems was 127m. The FATS simultaneously transmitted sound pulses from the 30 kHz omnidirectional transducers every 60 seconds. The results showed that the underwater sound speed and the water temperature were 1482 m/s and 20.3 ˚C, respectively. The temperature sensor measured the surface temperature in the various points of the channel and confirmed the validity of the FATS measurement with the relative error of 5%. The estimated flow velocity was zero. Due to the water stagnation.  }, Keywords = {Remote sensing, Underwater acoustic tomography, Underwater sound speed, Flow temperature, Flow velocity.}, volume = {6}, Number = {1}, pages = {1-11}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-125-en.html}, eprint = {http://joasi.ir/article-1-125-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Setvati-Zirak, A. and Momeni-Masuleh, S.H. and Massah, H.R.}, title = {Solution of propagation of acoustic-gravity waves in the atmosphere using finite difference method of order two}, abstract ={Investigating waves propagation’s equation in the atmosphere is one of the important and widely used issues in various sciences, which has attracted many researchers. A type of propagating waves is an acoustic-gravity wave. These type of waves have a lot of stationarity properties and can be propagate to a high altitude in the atmosphere. The equation of acoustic-gravity wave propagation is a hyperbolic nonlinear hydrodynamic equation consisting of continuity, motion, and energy equations. To obtain the solution of the acoustic-gravity waves propagation equation, the related hydrodynamic equations are written in the form of a conservation equation. In the next step, the propagation of the acoustic-gravity wave is simulated in the atmosphere using a two-stage Lax-Wendroff method, which is a finite difference method with a second order accuracy in place and time.}, Keywords = {Acoustic-gravity waves, Atmosphere, Tow-stage Lax-Wendroff, Finite difference, Hyperbolic equation.}, volume = {6}, Number = {1}, pages = {12-20}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-117-en.html}, eprint = {http://joasi.ir/article-1-117-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Soleimani, E. and Mokhtari-Dizaji, M. and Fatouraee, N. and Saberi, H.}, title = {Evaluating the effect of stenosis increase and pulsatile blood pressure on effective stress distribution in viscoelastic finite element model based on carotid artery ultrasound images}, abstract ={The aim of this study is to evaluate the changes of effective stress distribution in plaque by progressing to the stenosis throat and to assess the pulsatile pulse pressure effect on effective stress of a viscoelastic finite-element model of carotid arteries having less and more than 50% stenosis. In-vivo geometries of the arteries were reconstructed using consecutive transverse ultrasound images. Pulse pressure waveform exerted on the artery walls and Kelvin viscoelastic model parameters were extracted from consecutive longitudinal ultrasound image processing. According to the results of this study, the effective stress applied to the mild stenotic plaque decreases with progression to the throat and there after increases again. However, in more than 50% stenosis, thickness of the layer between the plaque component and artery lumen determines the trend of effective stress exerted on different sites of the plaque. Moreover, results showed that regardless of extremum effective stress locations in different cross-sections, maximum differences between the extremum effective stresses of different cross-sections accure in systole whilst in the beginning and end parts of the cardiac cycle differences are not considerable. It seems that this viscoelastic model can be used for accurate evaluation of stress distribution during the atherosclerotic stenosis progress.  }, Keywords = {Ultrasounic horn, Microstreaming, Acoustic pressure, Measurment.}, volume = {6}, Number = {1}, pages = {21-31}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-110-en.html}, eprint = {http://joasi.ir/article-1-110-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Khalilabadi, M.R.}, title = {Investigation on acoustic behavior of acoustic porous absorbers to ‎absorb sound energy and transmission loss index}, abstract ={In this study, the acoustic properties of porous absorbents with different porosity levels have been evaluated using different mathematical models. These models use one or more parameters of materials for calculating acoustic characteristics. In all of these models, materials are considered as equivalent fluid and reactionary characteristics have not been taken into account.}, Keywords = {Transmission loss, Sound absorption, Porous absorbent, Porosity, Acoustic characteristics.}, volume = {6}, Number = {1}, pages = {32-38}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-78-en.html}, eprint = {http://joasi.ir/article-1-78-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Talebitooti, R. and ChoudariKhameneh, A.M.}, title = {Modeling and simulation of the acoustic behavior of a muffler in a passenger car exhaust system}, abstract ={Muffler is one of the main components of an automotive exhaust system, which reduces the noise of the exhaust system. In this paper, modeling and simulation of the acoustic behavior of a muffler is presented with the aid of  an engineering software. For this purpose, firstly, an analytical model is presented to evaluate the sound transmission loss in cylindrical shells based on Sander's theory. Then, catalytic converter and muffler are modeled by considering the model's major dimensions in the engineering software. The comparison of the present results with previous studies shows the accuracy of the analytical model as well as the simulation results. In addition, the contour of sound pressure inside the catalytic converter and the muffler, as well as the direction of  the exhaust gas flow inside the muffler, indicate that the sound level created by Muffler is in the safe range according to the limitations posed by the standards.  }, Keywords = {Muffler, Acoustic behavior, Sound pressure, Sound energy.}, volume = {6}, Number = {1}, pages = {39-45}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-131-en.html}, eprint = {http://joasi.ir/article-1-131-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Valinejad, A.}, title = {Parallel implementation of underwater acoustic wave propagation using beamtracing method on graphical processing unit}, abstract ={The mathematical modeling of the acoustic wave propagation in seawater is the basis for realizing goals such as, underwater communication, seabed mapping, advanced fishing, oil and gas exploration, marine meteorology, positioning and explore the unknown targets within the water. However, due to the existence of various physical phenomena in the water environment and the various conditions governing the sea environment, such as, noise, sea state, depth, substrate, temperature and salinity, various methods have been proposed for the propagation of acoustic wave, which results in a high computational complexity in the numerical solution of acoustic wave propagation. Since the high speed of computing is a key factor in most real-time applications, in this study, a parallel algorithm for the implementation of computerized underwater acoustic wave propagation is presented, using the Gaussian Beamtracing method. In order to compare the performance of the proposed parallel algorithm with respect to the serial mode, the results are reported in figure and table for several different scenarios. The simulation results indicate a much higher rate of parallel algorithm than the serial mode despite its very precise accuracy.  }, Keywords = {Underwater acoustic wave propagation, Helmholtz equation, Ray tracing method, Beamtracing method, Parallel computations}, volume = {6}, Number = {1}, pages = {46-58}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-128-en.html}, eprint = {http://joasi.ir/article-1-128-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Hajnorouzi, A. and Afzalzadeh, R.}, title = {A simple and novel method for acoustic streaming power measurement of ultrasonic horn}, abstract ={Ultrasonic horn with transfer of acoustic wave into an aqueous solution results in unique properties. When, transfer of sound wave into a liquid results in liquid movement in the direction of wave propagation which gradually loses its energy due to the viscous friction. This wave motion induces a flow which is known as acoustic streaming or micro-streaming. In this article, a simple innovative system is designed and built to measure the power generated by micro-streaming. By measuring and analyzing the physical relations, the micro-streaming power obtained for various amplitudes was between 0.5 to 2.61 watts and the maximum displacement of the tip acquired was between 8 to 25 micro-meter for this ultrasonic horn.}, Keywords = {Ultrasounic horn, Microstreaming, Acoustic pressure, Bubble cloud, Measurment.}, volume = {6}, Number = {1}, pages = {59-64}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-132-en.html}, eprint = {http://joasi.ir/article-1-132-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2018} } @article{ author = {Adelnia, A. and Mokhtari-Dizaji, M. and Hoseinkhani, S. and Bakhshandeh, M.}, title = {The effect of low intensity dual frequency ultrasonic waves on the viability of the B16-F10 melanoma cell}, abstract ={In this study, the effect of single and dual-frequency sonication on cell death of B16-F10 melanoma cells is investigated at constant temperature. Here, 20 groups were studied. The test groups consisted of: control and sham, 40 kHz (intensity: 0.24 W/cm2), 1 MHZ (intensity: 0.5 W/cm2) and the dual frequency groups which each frequency group included seven subgroups of 30, 120, 60, 150, 300, 600 and 1200 s. Cell viability was measured by MTT assay. The result demonstrated that the cell viability for 40 kHz with 30 s sonication time was 96%, which decreased to 6% by increasing the sonication time up to 1200 s. In dual frequency, cell viability decreased in all subgroups, and its amount ranges from 95% at a sonication time of 30 s to 3% at 1200 s sonication time. The same process happens for 1 MHz frequency with a lower relative slope (97% to 15% when sonication time increased from 30 s 1200 s). Ultrasound waves caused the B16-F10 melanoma cell death in constant temperature. Dual frequency sonication caused more cell death especially at higher sonication time, possibly due to cavitation.}, Keywords = {Ultrasonic wave, Dual frequency sonication, B16-F10 melanoma cell, Cell death, ultrasound.}, volume = {6}, Number = {2}, pages = {1-8}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-139-en.html}, eprint = {http://joasi.ir/article-1-139-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2019} } @article{ author = {ZahediSalangooch, F. and Housaindokht, M.R. and Jalal, R. and Nakhaeipour, A. and IzadiNajafabadi, R.}, title = {Ultrasound effects on the activity of free and immobilized urease on the magnetic nanoparticles and silica gel}, abstract ={In this study, the effect of low-frequency ultrasound on the structure and activity of urease enzyme has been investigated. For this purpose, the enzyme was exposed to ultrasound with 20 kHz frequency at different time intervals. The urease enzyme was immobilized on the surface of magnetic nanoparticles (Fe2O3), and activated silica gel with 89% and 66% efficiency respectively. The enzyme activity, kinetic parameters, optimum pH and temperature were determined for free and immobilized enzymes at different conditions. The structure change of free enzymes caused by ultrasound was vreified by fluorescence and UV spectrum. The activity of enzyme was amplified in the presence of ultrasound. A reduction in the activity and Vmax and an increase in Km were observed for both free and immobilized enzymes on the activated silica gel after ultrasound treatment. While, ultrasound had no effect on the immobilized enzymes on the magnetic nanoparticles.}, Keywords = {Urease, Ultrasound wave, Enzyme immobilization, Fe2O3 magnetic nanoparticle, Silica gel.}, volume = {6}, Number = {2}, pages = {9-20}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-122-en.html}, eprint = {http://joasi.ir/article-1-122-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2019} } @article{ author = {Khalilabadi, M.R. and Shahmirzaeei, H.}, title = {Effect of porosity on the characteristics of underwater acoustic sound absorbers using theoretical models‎}, abstract ={Porous materials have good acoustic damping characteristics over a wide frequency range. As for sound waves, many small-scale pores in the coating materials can convert underwater-coating to rough surfaces. The main property of porous absorbents is their resistance against incident sound wave that leads to damping effect. From a physical point of view, damping occurs due to friction between fluid molecules inside the cavity and absorbent structure. In this study, the acoustic properties of porous absorbents with different porosity levels have been evaluated using different mathematical models. These models use one or more parameters of materials for calculating acoustic characteristics. In all of these models, materials are considered as equivalent fluid and reactionary characteristics have not been into account.  }, Keywords = {Sound absorption, Porous absorbent, Porosity, Acoustic characteristic.}, volume = {6}, Number = {2}, pages = {21-28}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-87-en.html}, eprint = {http://joasi.ir/article-1-87-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2019} } @article{ author = {Bahreinimotlagh, M. and Roozbahani, R. and Eftekhari, M. and Zareian, M.J. and Farokhnia, A.}, title = {Evaluation of underwater acoustic propagation model (Ray theory) in a river using Fluvial Acoustic Tomography System}, abstract ={Underwater acoustics is widely used in many applications, such as oceanography, marine biology, hydrography, fishery, etc. Different models are introduced to simulate the underwater acoustic propagation in the oceans and the seas. In this study, the Ray Theory model is used to simulate the acoustic wave propagation in a shallow-freshwater river (Gono River) located in western part of Japan. The Fluvial Acoustic Tomography System (FATS) evaluated the accuracy of the model estimations. The vertical sound speed profiles were measured by a CTD in the five positions and they were used as the model inputs. The simulation results showed two main groups of acoustic waves that propagated in different paths. The reasons were because of the riverbed topography and the flow velocity. Whilst, in the sea and the ocean, the temperature/salinity gradient and the existence of internal waves are the reasons of the acoustic propagation in different paths. The lag time between the arrival time of two ray groups was 0.5 msec. The FATS transducers were deployed on both sides of the river, where, the transmission length was set to 294.629 m and the central acoustic frequency was set to 30 kHz. Finally, the FATS measurements confirmed the model results.  }, Keywords = {Underwater acoustic wave propagation, Ray theory, Shallow-freshwater river, FATS.}, volume = {6}, Number = {2}, pages = {29-38}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-123-en.html}, eprint = {http://joasi.ir/article-1-123-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2019} } @article{ author = {GhasemiYeklangi, A. and EsmaeelzadehKhadem, S.}, title = {Fabrication and investigation of a transparent and flexible loudspeaker and microphone based on carbon nanotube}, abstract ={Transparent acoustic sensors and actuators are a new generation of acoustic transducers that can create an evolution in the microphone and loudspeakers industries. These transducers with properties like transparency, flexibility, flatness, very low weight and thickness have a great potential for various applications like public speakers, active noise cancelation systems, displays, cell phones and hidden microphones. In this investigation, fabrication of a prototype of these transparent transducers was the goal. In this research with coating multi wall carbon nanotube on PVDF substrate, a transparent acoustic sensor and actuator system was fabricated and characterized. After production of Carbon nanotube dispersed solution and surface modification of PVDF substrate, dip coating method was used for coating of CNTs on substrate. A coating with 75% transparency and surface resistance of 2.2 kΩ/sq was created. Then the fabricated transducer was tested in an anechoic chamber and results were compared with those of earlier researches. The fabricated transducer produced 58 dB sound under excitation with 25 V white noise.}, Keywords = {Acoustic sensor and actuator, Carbon Nanotube, Flexible loudspeaker.}, volume = {6}, Number = {2}, pages = {39-45}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-134-en.html}, eprint = {http://joasi.ir/article-1-134-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2019} } @article{ author = {RahmatiAhmadabadi, M. and EsmaeelzadehKhadem, S. and Rasekh, M.}, title = {Design and performance analysis of a seismic grade resonance nano accelerometer}, abstract ={In this paper, design and performance analysis of a resonance nanosensor for earthquake low frequency geoacoustic waves detection is proposed. The model comprises of a proof mass suspended to the substrate, and a nanobeam attached to the intersection of the proof mass to the substrate. The nanobeam could be cosidered as a clamped-clamped nanoresonator actuated electrostartically. The induced accelaration to the proof mass could lead to an axial tensile or compression force in the nanoresonator. The axial induced force could change the system stored potential energy and result in the shift of the resonator natural frequncy. Measuring the frequncy shift of the resonator, could lead to the estimation of the applied accelaration to the proof mass. Furthermore, the nanobeam is laminated between two piezoelectric layers wich applying voltage to them could improve the perfomance of the nanosensor. Governing equations are obtained using Hamilonian’s principle that considers the main sources of nonlinearity including electrostatic fringing field effect, piezoelectric and casimir force, and stretching effect. The equations are solved using numerical and analytical methods. The simulation results are being used to investigate the nanosensor performance charactersitics including the device dynamic response, resolution, sensitivity, bandwidth, dynamic range and the structural resitance. The results show that the proposed nano accelerometer could have a better performance compared the existing micro and macro earthquake detection devices measuring geoacoustic infrasonic and low frequency waves.  }, Keywords = {Nanosensor, Earthquake detection, Nonliear dynamics, Resonator, Multiple time scales method, Infrasonic, Geoacoustic.}, volume = {6}, Number = {2}, pages = {46-59}, publisher = {Acoustical Society of Iran}, url = {http://joasi.ir/article-1-136-en.html}, eprint = {http://joasi.ir/article-1-136-en.pdf}, journal = {Journal of Acoustical Society of Iran}, issn = {2345-5748}, eissn = {2345-5748}, year = {2019} }