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class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 1791</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: acoustic channel</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1791</span> Multi-Sender MAC Protocol Based on Temporal Reuse in Underwater Acoustic Networks</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dongwon%20Lee">Dongwon Lee</a>, <a href="https://publications.waset.org/abstracts/search?q=Sunmyeng%20Kim"> Sunmyeng Kim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Underwater acoustic networks (UANs) have become a very active research area in recent years. Compared with wireless networks, UANs are characterized by the limited bandwidth, long propagation delay and high channel dynamic in acoustic modems, which pose challenges to the design of medium access control (MAC) protocol. The characteristics severely affect network performance. In this paper, we study a MS-MAC (Multi-Sender MAC) protocol in order to improve network performance. The proposed protocol exploits temporal reuse by learning the propagation delays to neighboring nodes. A source node locally calculates the transmission schedules of its neighboring nodes and itself based on the propagation delays to avoid collisions. Performance evaluation is conducted using simulation, and confirms that the proposed protocol significantly outperforms the previous protocol in terms of throughput. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20channel" title="acoustic channel">acoustic channel</a>, <a href="https://publications.waset.org/abstracts/search?q=MAC" title=" MAC"> MAC</a>, <a href="https://publications.waset.org/abstracts/search?q=temporal%20reuse" title=" temporal reuse"> temporal reuse</a>, <a href="https://publications.waset.org/abstracts/search?q=UAN" title=" UAN"> UAN</a> </p> <a href="https://publications.waset.org/abstracts/43015/multi-sender-mac-protocol-based-on-temporal-reuse-in-underwater-acoustic-networks" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/43015.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">355</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1790</span> Particle Gradient Generation in a Microchannel Using a Single IDT</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Florian%20Kiebert">Florian Kiebert</a>, <a href="https://publications.waset.org/abstracts/search?q=Hagen%20Schmidt"> Hagen Schmidt</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Standing surface acoustic waves (sSAWs) have already been used to manipulate particles in a microfluidic channel made of polydimethylsiloxan (PDMS). Usually two identical facing interdigital transducers (IDTs) are exploited to form an sSAW. Further, it has been reported that an sSAW can be generated by a single IDT using a superstrate resonating cavity or a PDMS post. Nevertheless, both setups utilising a traveling surface acoustic wave (tSAW) to create an sSAW for particle manipulation are costly. We present a simplified setup with a tSAW and a PDMS channel to form an sSAW. The incident tSAW is reflected at the rear PDMS channel wall and superimposed with the reflected tSAW. This superpositioned waves generates an sSAW but only at regions where the distance to the rear channel wall is smaller as the attenuation length of the tSAW minus the channel width. Therefore in a channel of 500µm width a tSAW with a wavelength λ = 120 µm causes a sSAW over the whole channel, whereas a tSAW with λ = 60 µm only forms an sSAW next to the rear wall of the channel, taken into account the attenuation length of a tSAW in water. Hence, it is possible to concentrate and trap particles in a defined region of the channel by adjusting the relation between the channel width and tSAW wavelength. Moreover, it is possible to generate a particle gradient over the channel width by picking the right ratio between channel wall and wavelength. The particles are moved towards the rear wall by the acoustic streaming force (ASF) and the acoustic radiation force (ARF) caused by the tSAW generated bulk acoustic wave (BAW). At regions in the channel were the sSAW is dominating the ARF focuses the particles in the pressure nodes formed by the sSAW caused BAW. On the one side the ARF generated by the sSAW traps the particle at the center of the tSAW beam, i. e. of the IDT aperture. On the other side, the ASF leads to two vortices, one on the left and on the right side of the focus region, deflecting the particles out of it. Through variation of the applied power it is possible to vary the number of particles trapped in the focus points, because near to the rear wall the amplitude of the reflected tSAW is higher and, therefore, the ARF of the sSAW is stronger. So in the vicinity of the rear wall the concentration of particles is higher but decreases with increasing distance to the wall, forming a gradient of particles. The particle gradient depends on the applied power as well as on the flow rate. Thus by variation of these two parameters it is possible to change the particle gradient. Furthermore, we show that the particle gradient can be modified by changing the relation between the channel width and tSAW wavelength. Concluding a single IDT generates an sSAW in a PDMS microchannel enables particle gradient generation in a well-defined microfluidic flow system utilising the ARF and ASF of a tSAW and an sSAW. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ARF" title="ARF">ARF</a>, <a href="https://publications.waset.org/abstracts/search?q=ASF" title=" ASF"> ASF</a>, <a href="https://publications.waset.org/abstracts/search?q=particle%20manipulation" title=" particle manipulation"> particle manipulation</a>, <a href="https://publications.waset.org/abstracts/search?q=sSAW" title=" sSAW"> sSAW</a>, <a href="https://publications.waset.org/abstracts/search?q=tSAW" title=" tSAW "> tSAW </a> </p> <a href="https://publications.waset.org/abstracts/37810/particle-gradient-generation-in-a-microchannel-using-a-single-idt" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/37810.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">341</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1789</span> The Condition Testing of Damaged Plates Using Acoustic Features and Machine Learning</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kyle%20Saltmarsh">Kyle Saltmarsh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Acoustic testing possesses many benefits due to its non-destructive nature and practicality. There hence exists many scenarios in which using acoustic testing for condition testing shows powerful feasibility. A wealth of information is contained within the acoustic and vibration characteristics of structures, allowing the development meaningful features for the classification of their respective condition. In this paper, methods, results, and discussions are presented on the use of non-destructive acoustic testing coupled with acoustic feature extraction and machine learning techniques for the condition testing of manufactured circular steel plates subjected to varied levels of damage. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=plates" title="plates">plates</a>, <a href="https://publications.waset.org/abstracts/search?q=deformation" title=" deformation"> deformation</a>, <a href="https://publications.waset.org/abstracts/search?q=acoustic%20features" title=" acoustic features"> acoustic features</a>, <a href="https://publications.waset.org/abstracts/search?q=machine%20learning" title=" machine learning"> machine learning</a> </p> <a href="https://publications.waset.org/abstracts/76911/the-condition-testing-of-damaged-plates-using-acoustic-features-and-machine-learning" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/76911.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">340</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1788</span> Mixing Enhancement with 3D Acoustic Streaming Flow Patterns Induced by Trapezoidal Triangular Structure Micromixer Using Different Mixing Fluids</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ayalew%20Yimam%20%20Ali">Ayalew Yimam Ali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The T-shaped microchannel is used to mix both miscible or immiscible fluids with different viscosities. However, mixing at the entrance of the T-junction microchannel can be difficult mixing phenomena due to micro-scale laminar flow aspects with the two miscible high-viscosity water-glycerol fluids. One of the most promising methods to improve mixing performance and diffusion mass transfer in laminar flow phenomena is acoustic streaming (AS), which is a time-averaged, second-order steady streaming that can produce rolling motion in the microchannel by oscillating a low-frequency range acoustic transducer and inducing an acoustic wave in the flow field. The newly developed 3D trapezoidal, triangular structure spine used in this study was created using sophisticated CNC machine cutting tools used to create microchannel mold with a 3D trapezoidal triangular structure spine alone the T-junction longitudinal mixing region. In order to create the molds for the 3D trapezoidal structure with the 3D sharp edge tip angles of 30° and 0.3mm trapezoidal, triangular sharp edge tip depth from PMMA glass (Polymethylmethacrylate) with advanced CNC machine and the channel manufactured using PDMS (Polydimethylsiloxane) which is grown up longitudinally on the top surface of the Y-junction microchannel using soft lithography nanofabrication strategies. Flow visualization of 3D rolling steady acoustic streaming and mixing enhancement with high-viscosity miscible fluids with different trapezoidal, triangular structure longitudinal length, channel width, high volume flow rate, oscillation frequency, and amplitude using micro-particle image velocimetry (μPIV) techniques were used to study the 3D acoustic streaming flow patterns and mixing enhancement. The streaming velocity fields and vorticity flow fields show 16 times more high vorticity maps than in the absence of acoustic streaming, and mixing performance has been evaluated at various amplitudes, flow rates, and frequencies using the grayscale value of pixel intensity with MATLAB software. Mixing experiments were performed using fluorescent green dye solution with de-ionized water in one inlet side of the channel, and the de-ionized water-glycerol mixture on the other inlet side of the T-channel and degree of mixing was found to have greatly improved from 67.42% without acoustic streaming to 0.96.83% with acoustic streaming. The results show that the creation of a new 3D steady streaming rolling motion with a high volume flowrate around the entrance was enhanced by the formation of a new, three-dimensional, intense streaming rolling motion with a high-volume flowrate around the entrance junction mixing zone with the two miscible high-viscous fluids which are influenced by laminar flow fluid transport phenomena. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=micro%20fabrication" title="micro fabrication">micro fabrication</a>, <a href="https://publications.waset.org/abstracts/search?q=3d%20acoustic%20streaming%20flow%20visualization" title=" 3d acoustic streaming flow visualization"> 3d acoustic streaming flow visualization</a>, <a href="https://publications.waset.org/abstracts/search?q=micro-particle%20image%20velocimetry" title=" micro-particle image velocimetry"> micro-particle image velocimetry</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing%20enhancement." title=" mixing enhancement."> mixing enhancement.</a> </p> <a href="https://publications.waset.org/abstracts/190156/mixing-enhancement-with-3d-acoustic-streaming-flow-patterns-induced-by-trapezoidal-triangular-structure-micromixer-using-different-mixing-fluids" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/190156.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">29</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1787</span> Using Probabilistic Neural Network (PNN) for Extracting Acoustic Microwaves (Bulk Acoustic Waves) in Piezoelectric Material</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hafdaoui%20Hichem">Hafdaoui Hichem</a>, <a href="https://publications.waset.org/abstracts/search?q=Mehadjebia%20Cherifa"> Mehadjebia Cherifa</a>, <a href="https://publications.waset.org/abstracts/search?q=Benatia%20Djamel"> Benatia Djamel</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we propose a new method for Bulk detection of an acoustic microwave signal during the propagation of acoustic microwaves in a piezoelectric substrate (Lithium Niobate LiNbO3). We have used the classification by probabilistic neural network (PNN) as a means of numerical analysis in which we classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity in order to build a model from which we note the Bulk waves easily. These singularities inform us of presence of Bulk waves in piezoelectric materials. By which we obtain accurate values for each of the coefficient attenuation and acoustic velocity for Bulk waves. This study will be very interesting in modeling and realization of acoustic microwaves devices (ultrasound) based on the propagation of acoustic microwaves. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=piezoelectric%20material" title="piezoelectric material">piezoelectric material</a>, <a href="https://publications.waset.org/abstracts/search?q=probabilistic%20neural%20network%20%28PNN%29" title=" probabilistic neural network (PNN)"> probabilistic neural network (PNN)</a>, <a href="https://publications.waset.org/abstracts/search?q=classification" title=" classification"> classification</a>, <a href="https://publications.waset.org/abstracts/search?q=acoustic%20microwaves" title=" acoustic microwaves"> acoustic microwaves</a>, <a href="https://publications.waset.org/abstracts/search?q=bulk%20waves" title=" bulk waves"> bulk waves</a>, <a href="https://publications.waset.org/abstracts/search?q=the%20attenuation%20coefficient" title=" the attenuation coefficient"> the attenuation coefficient</a> </p> <a href="https://publications.waset.org/abstracts/43264/using-probabilistic-neural-network-pnn-for-extracting-acoustic-microwaves-bulk-acoustic-waves-in-piezoelectric-material" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/43264.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">438</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1786</span> Flow Visualization and Mixing Enhancement in Y-Junction Microchannel with 3D Acoustic Streaming Flow Patterns Induced by Trapezoidal Triangular Structure using High-Viscous Liquids</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ayalew%20Yimam%20Ali">Ayalew Yimam Ali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Y-shaped microchannel is used to mix both miscible or immiscible fluids with different viscosities. However, mixing at the entrance of the Y-junction microchannel can be a difficult mixing phenomena due to micro-scale laminar flow aspects with the two miscible high-viscosity water-glycerol fluids. One of the most promising methods to improve mixing performance and diffusion mass transfer in laminar flow phenomena is acoustic streaming (AS), which is a time-averaged, second-order steady streaming that can produce rolling motion in the microchannel by oscillating a low-frequency range acoustic transducer and inducing an acoustic wave in the flow field. The developed 3D trapezoidal, triangular structure spine used in this study was created using sophisticated CNC machine cutting tools used to create microchannel mold with a 3D trapezoidal triangular structure spine alone the Y-junction longitudinal mixing region. In order to create the molds for the 3D trapezoidal structure with the 3D sharp edge tip angles of 30° and 0.3mm trapezoidal triangular sharp edge tip depth from PMMA glass (Polymethylmethacrylate) with advanced CNC machine and the channel manufactured using PDMS (Polydimethylsiloxane) which is grown up longitudinally on top surface of the Y-junction microchannel using soft lithography nanofabrication strategies. Flow visualization of 3D rolling steady acoustic streaming and mixing enhancement with high-viscosity miscible fluids with different trapezoidal, triangular structure longitudinal length, channel width, high volume flow rate, oscillation frequency, and amplitude using micro-particle image velocimetry (μPIV) techniques were used to study the 3D acoustic streaming flow patterns and mixing enhancement. The streaming velocity fields and vorticity flow fields show 16 times more high vorticity maps than in the absence of acoustic streaming, and mixing performance has been evaluated at various amplitudes, flow rates, and frequencies using the grayscale value of pixel intensity with MATLAB software. Mixing experiments were performed using fluorescent green dye solution with de-ionized water in one inlet side of the channel, and the de-ionized water-glycerol mixture on the other inlet side of the Y-channel and degree of mixing was found to have greatly improved from 67.42% without acoustic streaming to 0.96.83% with acoustic streaming. The results show that the creation of a new 3D steady streaming rolling motion with a high volume flowrate around the entrance was enhanced by the formation of a new, three-dimensional, intense streaming rolling motion with a high-volume flowrate around the entrance junction mixing zone with the two miscible high-viscous fluids which are influenced by laminar flow fluid transport phenomena. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=micro%20fabrication" title="micro fabrication">micro fabrication</a>, <a href="https://publications.waset.org/abstracts/search?q=3d%20acoustic%20streaming%20flow%20visualization" title=" 3d acoustic streaming flow visualization"> 3d acoustic streaming flow visualization</a>, <a href="https://publications.waset.org/abstracts/search?q=micro-particle%20image%20velocimetry" title=" micro-particle image velocimetry"> micro-particle image velocimetry</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing%20enhancement" title=" mixing enhancement"> mixing enhancement</a> </p> <a href="https://publications.waset.org/abstracts/190153/flow-visualization-and-mixing-enhancement-in-y-junction-microchannel-with-3d-acoustic-streaming-flow-patterns-induced-by-trapezoidal-triangular-structure-using-high-viscous-liquids" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/190153.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">30</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1785</span> Numerical and Experimental Study of Heat Transfer Enhancement with Metal Foams and Ultrasounds</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=L.%20Slimani">L. Slimani</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Bousri"> A. Bousri</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Hamadouche"> A. Hamadouche</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Ben%20Hamed"> H. Ben Hamed</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The aim of this experimental and numerical study is to analyze the effects of acoustic streaming generated by 40 kHz ultrasonic waves on heat transfer in forced convection, with and without 40 PPI aluminum metal foam. Preliminary dynamic and thermal studies were done with COMSOL Multiphase, to see heat transfer enhancement degree by inserting a 40PPI metal foam (10 × 2 × 3 cm) on a heat sink, after having determined experimentally its permeability and Forchheimer's coefficient. The results obtained numerically are in accordance with those obtained experimentally, with an enhancement factor of 205% for a velocity of 0.4 m/s compared to an empty channel. The influence of 40 kHz ultrasound on heat transfer was also tested with and without metallic foam. Results show a remarkable increase in Nusselt number in an empty channel with an enhancement factor of 37,5%, while no influence of ultrasound on heat transfer in metal foam presence. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20streaming" title="acoustic streaming">acoustic streaming</a>, <a href="https://publications.waset.org/abstracts/search?q=enhancing%20heat%20transfer" title=" enhancing heat transfer"> enhancing heat transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=laminar%20flow" title=" laminar flow"> laminar flow</a>, <a href="https://publications.waset.org/abstracts/search?q=metal%20foam" title=" metal foam"> metal foam</a>, <a href="https://publications.waset.org/abstracts/search?q=ultrasound" title=" ultrasound"> ultrasound</a> </p> <a href="https://publications.waset.org/abstracts/135365/numerical-and-experimental-study-of-heat-transfer-enhancement-with-metal-foams-and-ultrasounds" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/135365.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">142</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1784</span> Effects of Charge Fluctuating Positive Dust on Linear Dust-Acoustic Waves </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sanjit%20Kumar%20Paul">Sanjit Kumar Paul</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20A.%20Mamun"> A. A. Mamun</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20R.%20Amin"> M. R. Amin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Linear propagation of the dust-acoustic wave in a dusty plasma consisting of Boltzmann distributed electrons and ions and mobile charge fluctuating positive dust grains has been investigated by employing the reductive perturbation method. It has been shown that the dust charge fluctuation is a source of dissipation and its responsible for the formation of the dust-acoustic waves in such a dusty plasma. The basic features of such dust-acoustic waves have been identified. It has been proposed to design a new laboratory experiment which will be able to identify the basic features of the dust-acoustic waves predicted in this theoretical investigation. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=dust%20acoustic%20waves" title="dust acoustic waves">dust acoustic waves</a>, <a href="https://publications.waset.org/abstracts/search?q=dusty%20plasma" title=" dusty plasma"> dusty plasma</a>, <a href="https://publications.waset.org/abstracts/search?q=Boltzmann%20distributed%20electrons" title=" Boltzmann distributed electrons"> Boltzmann distributed electrons</a>, <a href="https://publications.waset.org/abstracts/search?q=charge%20fluctuation" title=" charge fluctuation"> charge fluctuation</a> </p> <a href="https://publications.waset.org/abstracts/8380/effects-of-charge-fluctuating-positive-dust-on-linear-dust-acoustic-waves" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/8380.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">645</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1783</span> A Simplified, Fabrication-Friendly Acoustophoretic Model for Size Sensitive Particle Sorting</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=V.%20Karamzadeh">V. Karamzadeh</a>, <a href="https://publications.waset.org/abstracts/search?q=J.%20Adhvaryu"> J. Adhvaryu</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Chandrasekaran"> A. Chandrasekaran</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Packirisamy"> M. Packirisamy</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In Bulk Acoustic Wave (BAW) microfluidics, the throughput of particle sorting is dependent on the complex interplay between the geometric configuration of the channel, the size of the particles, and the properties of the fluid medium, which therefore calls for a detailed modeling and understanding of the fluid-particle interaction dynamics under an acoustic field, prior to designing the system. In this work, we propose a simplified Bulk acoustophoretic system that can be used for size dependent particle sorting. A Finite Element Method (FEM) based analytical model has been developed to study the dependence of particle sizes on channel parameters, and the sorting efficiency in a given fluid medium. Based on the results, the microfluidic system has been designed to take into account all the variables involved with the underlying physics, and has been fabricated using an additive manufacturing technique employing a commercial 3D printer, to generate a simple, cost-effective system that can be used for size sensitive particle sorting. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=3D%20printing" title="3D printing">3D printing</a>, <a href="https://publications.waset.org/abstracts/search?q=3D%20microfluidic%20chip" title=" 3D microfluidic chip"> 3D microfluidic chip</a>, <a href="https://publications.waset.org/abstracts/search?q=acoustophoresis" title=" acoustophoresis"> acoustophoresis</a>, <a href="https://publications.waset.org/abstracts/search?q=cell%20separation" title=" cell separation"> cell separation</a>, <a href="https://publications.waset.org/abstracts/search?q=MEMS%20%28Microelectromechanical%20Systems%29" title=" MEMS (Microelectromechanical Systems)"> MEMS (Microelectromechanical Systems)</a>, <a href="https://publications.waset.org/abstracts/search?q=microfluidics" title=" microfluidics"> microfluidics</a> </p> <a href="https://publications.waset.org/abstracts/83336/a-simplified-fabrication-friendly-acoustophoretic-model-for-size-sensitive-particle-sorting" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/83336.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">177</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1782</span> Opportunities and Challenges of Omni Channel Retailing in the Emerging Market</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Salma%20Ahmed">Salma Ahmed</a>, <a href="https://publications.waset.org/abstracts/search?q=Anil%20Kumar"> Anil Kumar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper develops and estimates a model for understanding the drivers and barriers for Omni-Channel retail. This study serves as one of the first attempt to empirically test the effect of various factors on Omni-channel retail. Omni-channel is relative new and evolving, we hypothesize three drivers: (1) Innovative sales and marketing opportunities, (2) channel migration, (3) Cross channel synergies; and three barriers: (1) Integrated sales and marketing operations, (2) Visibility and synchronization (3) Integration and Technology challenges. The findings from the study strongly support that Omni-channel effects exist between cross channel synergy and channel migration. However, it partially supports innovative sales and marketing operations. We also found the variables which we identified as barriers to Omni-channel retail have a strong impact on Omni-channel retail. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=retailing" title="retailing">retailing</a>, <a href="https://publications.waset.org/abstracts/search?q=multichannel" title=" multichannel"> multichannel</a>, <a href="https://publications.waset.org/abstracts/search?q=Omni-channel" title=" Omni-channel"> Omni-channel</a>, <a href="https://publications.waset.org/abstracts/search?q=emerging%20market" title=" emerging market "> emerging market </a> </p> <a href="https://publications.waset.org/abstracts/24135/opportunities-and-challenges-of-omni-channel-retailing-in-the-emerging-market" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/24135.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">558</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1781</span> ReS, Resonant String Shell: Development of an Acoustic Shell for Outdoor Chamber Music Concerts</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Serafino%20Di%20Rosario">Serafino Di Rosario</a> </p> <p class="card-text"><strong>Abstract:</strong></p> ReS is a sustainable hand-built temporary acoustic shell, developed since 2011 and built during the architectural workshop at Villa Pennisi in Musica in Acireale, Sicily, each year since 2012. The design concept aims to provide a portable structure by reducing the on-site construction problems and the skills required by the builders together with maximizing the acoustic performance for the audience and the musicians. The shell is built using only wood, recycled for the most part, and can be built and dismantled by non-specialized workers in just three days. This paper describes the research process, which spans over four years and presents the final results in form of acoustic simulations performed by acoustic modeling software and real world measurements. ReS is developed by the ReS team who has been presented with the Peter Lord Award in 2015 by the Institute of Acoustics in the UK. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20shell" title="acoustic shell">acoustic shell</a>, <a href="https://publications.waset.org/abstracts/search?q=outdoor%20natural%20amplification" title=" outdoor natural amplification"> outdoor natural amplification</a>, <a href="https://publications.waset.org/abstracts/search?q=computational%20design" title=" computational design"> computational design</a>, <a href="https://publications.waset.org/abstracts/search?q=room%20acoustics" title=" room acoustics"> room acoustics</a> </p> <a href="https://publications.waset.org/abstracts/67117/res-resonant-string-shell-development-of-an-acoustic-shell-for-outdoor-chamber-music-concerts" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/67117.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">233</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1780</span> Analytical Solutions for Geodesic Acoustic Eigenmodes in Tokamak Plasmas</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Victor%20I.%20Ilgisonis">Victor I. Ilgisonis</a>, <a href="https://publications.waset.org/abstracts/search?q=Ludmila%20V.%20Konovaltseva"> Ludmila V. Konovaltseva</a>, <a href="https://publications.waset.org/abstracts/search?q=Vladimir%20P.%20Lakhin"> Vladimir P. Lakhin</a>, <a href="https://publications.waset.org/abstracts/search?q=Ekaterina%20A.%20Sorokina"> Ekaterina A. Sorokina</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The analytical solutions for geodesic acoustic eigenmodes in tokamak plasmas with circular concentric magnetic surfaces are found. In the frame of ideal magnetohydrodynamics the dispersion relation taking into account the toroidal coupling between electrostatic perturbations and electromagnetic perturbations with poloidal mode number |m| = 2 is derived. In the absence of such a coupling the dispersion relation gives the standard continuous spectrum of geodesic acoustic modes. The analysis of the existence of global eigenmodes for plasma equilibria with both off-axis and on-axis maximum of the local geodesic acoustic frequency is performed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=tokamak" title="tokamak">tokamak</a>, <a href="https://publications.waset.org/abstracts/search?q=MHD" title=" MHD"> MHD</a>, <a href="https://publications.waset.org/abstracts/search?q=geodesic%20acoustic%20mode" title=" geodesic acoustic mode"> geodesic acoustic mode</a>, <a href="https://publications.waset.org/abstracts/search?q=eigenmode" title=" eigenmode"> eigenmode</a> </p> <a href="https://publications.waset.org/abstracts/11335/analytical-solutions-for-geodesic-acoustic-eigenmodes-in-tokamak-plasmas" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/11335.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">739</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1779</span> Test Research on Damage Initiation and Development of a Concrete Beam Using Acoustic Emission Technology</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Xiang%20Wang">Xiang Wang</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In order to validate the efficiency of recognizing the damage initiation and development of a concrete beam using acoustic emission technology, a concrete beam is built and tested in the laboratory. The acoustic emission signals are analyzed based on both parameter and wave information, which is also compared with the beam deflection measured by displacement sensors. The results indicate that using acoustic emission technology can detect damage initiation and development effectively, especially in the early stage of the damage development, which can not be detected by the common monitoring technology. Furthermore, the positioning of the damage based on the acoustic emission signals can be proved to be reasonable. This job can be an important attempt for the future long-time monitoring of the real concrete structure. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20emission%20technology" title="acoustic emission technology">acoustic emission technology</a>, <a href="https://publications.waset.org/abstracts/search?q=concrete%20beam" title=" concrete beam"> concrete beam</a>, <a href="https://publications.waset.org/abstracts/search?q=parameter%20analysis" title=" parameter analysis"> parameter analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=wave%20analysis" title=" wave analysis"> wave analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=positioning" title=" positioning"> positioning</a> </p> <a href="https://publications.waset.org/abstracts/108497/test-research-on-damage-initiation-and-development-of-a-concrete-beam-using-acoustic-emission-technology" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/108497.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">145</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1778</span> Flow Visualization and Mixing Enhancement in Y-Junction Microchannel with 3D Acoustic Streaming Flow Patterns Induced by Trapezoidal Triangular Structure using High-Viscous Liquids</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ayalew%20Yimam%20Ali">Ayalew Yimam Ali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Y-shaped microchannel system is used to mix up low or high viscosities of different fluids, and the laminar flow with high-viscous water-glycerol fluids makes the mixing at the entrance Y-junction region a challenging issue. Acoustic streaming (AS) is time-average, a steady second-order flow phenomenon that could produce rolling motion in the microchannel by oscillating low-frequency range acoustic transducer by inducing acoustic wave in the flow field is the promising strategy to enhance diffusion mass transfer and mixing performance in laminar flow phenomena. In this study, the 3D trapezoidal Structure has been manufactured with advanced CNC machine cutting tools to produce the molds of trapezoidal structure with the 3D sharp edge tip angles of 30° and 0.3mm spine sharp-edge tip depth from PMMA glass (Polymethylmethacrylate) and the microchannel has been fabricated using PDMS (Polydimethylsiloxane) which could be grown-up longitudinally in Y-junction microchannel mixing region top surface to visualized 3D rolling steady acoustic streaming and mixing performance evaluation using high-viscous miscible fluids. The 3D acoustic streaming flow patterns and mixing enhancement were investigated using the micro-particle image velocimetry (μPIV) technique with different spine depth lengths, channel widths, high volume flow rates, oscillation frequencies, and amplitude. The velocity and vorticity flow fields show that a pair of 3D counter-rotating streaming vortices were created around the trapezoidal spine structure and observing high vorticity maps up to 8 times more than the case without acoustic streaming in Y-junction with the high-viscosity water-glycerol mixture fluids. The mixing experiments were performed by using fluorescent green dye solution with de-ionized water on one inlet side, de-ionized water-glycerol with different mass-weight percentage ratios on the other inlet side of the Y-channel and evaluated its performance with the degree of mixing at different amplitudes, flow rates, frequencies, and spine sharp-tip edge angles using the grayscale value of pixel intensity with MATLAB Software. The degree of mixing (M) characterized was found to significantly improved to 0.96.8% with acoustic streaming from 67.42% without acoustic streaming, in the case of 0.0986 μl/min flow rate, 12kHz frequency and 40V oscillation amplitude at y = 2.26 mm. The results suggested the creation of a new 3D steady streaming rolling motion with a high volume flow rate around the entrance junction mixing region, which promotes the mixing of two similar high-viscosity fluids inside the microchannel, which is unable to mix by the laminar flow with low viscous conditions. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=nano%20fabrication" title="nano fabrication">nano fabrication</a>, <a href="https://publications.waset.org/abstracts/search?q=3D%20acoustic%20streaming%20flow%20visualization" title=" 3D acoustic streaming flow visualization"> 3D acoustic streaming flow visualization</a>, <a href="https://publications.waset.org/abstracts/search?q=micro-particle%20image%20velocimetry" title=" micro-particle image velocimetry"> micro-particle image velocimetry</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing%20enhancement" title=" mixing enhancement"> mixing enhancement</a> </p> <a href="https://publications.waset.org/abstracts/188950/flow-visualization-and-mixing-enhancement-in-y-junction-microchannel-with-3d-acoustic-streaming-flow-patterns-induced-by-trapezoidal-triangular-structure-using-high-viscous-liquids" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/188950.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">41</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1777</span> Acoustic Blood Plasmapheresis in Polymeric Resonators </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Itziar%20Gonzalez">Itziar Gonzalez</a>, <a href="https://publications.waset.org/abstracts/search?q=Pilar%20Carreras"> Pilar Carreras</a>, <a href="https://publications.waset.org/abstracts/search?q=Alberto%20Pinto"> Alberto Pinto</a>, <a href="https://publications.waset.org/abstracts/search?q=Roque%20Ruben%20Andres"> Roque Ruben Andres</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Acoustophoretic separation of plasma from blood is based on a collection process of the blood cells, driven by an acoustic radiation force. The number of cells, their concentration, and the sample hydrodynamics are involved in these processes. However, their influence on the acoustic blood response has not yet been reported in the literature. Addressing it, this paper presents an experimental study of blood samples exposed to ultrasonic standing waves at different hematocrit levels and hydrodynamic conditions. The experiments were performed in a glass capillary (700µm-square cross section) actuated by a piezoelectric ceramic at 1MHz, hosting 2D orthogonal half-wavelength resonances transverse to the channel length, with a single-pressure-node along its central axis where cells collected driven by the acoustic radiation force. Four blood dilutions in PBS of 1:20, 1:10, 1:5, and 1:2 were tested at eight flow rate conditions Q=0:120µL/min. The 1:5 dilution (H=9%) demonstrated to be optimal for the plasmapheresis at any of the flow rates analyzed, requiring the shortest times to achieve plasma free of cells. The study opens new possibilities to optimize processes of plasmapheresis processes by ultrasounds at different hematocrit conditions in future personalized diagnoses/treatments involving blood samples. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=ultrasounds" title="ultrasounds">ultrasounds</a>, <a href="https://publications.waset.org/abstracts/search?q=microfluidics" title=" microfluidics"> microfluidics</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20rate" title=" flow rate"> flow rate</a>, <a href="https://publications.waset.org/abstracts/search?q=acoustophoresis" title=" acoustophoresis"> acoustophoresis</a>, <a href="https://publications.waset.org/abstracts/search?q=polymeric%20resonators" title=" polymeric resonators"> polymeric resonators</a> </p> <a href="https://publications.waset.org/abstracts/125002/acoustic-blood-plasmapheresis-in-polymeric-resonators" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/125002.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">139</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1776</span> Modeling of Microelectromechanical Systems Diaphragm Based Acoustic Sensor</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Vasudha%20Hegde">Vasudha Hegde</a>, <a href="https://publications.waset.org/abstracts/search?q=Narendra%20Chaulagain"> Narendra Chaulagain</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20M.%20Ravikumar"> H. M. Ravikumar</a>, <a href="https://publications.waset.org/abstracts/search?q=Sonu%20Mishra"> Sonu Mishra</a>, <a href="https://publications.waset.org/abstracts/search?q=Siva%20Yellampalli"> Siva Yellampalli</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Acoustic sensors are extensively used in recent days not only for sensing and condition monitoring applications but also for small scale energy harvesting applications to power wireless sensor networks (WSN) due to their inherent advantages. The natural frequency of the structure plays a major role in energy harvesting applications since the sensor key element has to operate at resonant frequency. In this paper, circular diaphragm based MEMS acoustic sensor is modelled by Lumped Element Model (LEM) and the natural frequency is compared with the simulated model using Finite Element Method (FEM) tool COMSOL Multiphysics. The sensor has the circular diaphragm of 3000 µm radius and thickness of 30 µm to withstand the high SPL (Sound Pressure Level) and also to withstand the various fabrication steps. A Piezoelectric ZnO layer of thickness of 1 µm sandwiched between two aluminium electrodes of thickness 0.5 µm and is coated on the diaphragm. Further, a channel with radius 3000 µm radius and length 270 µm is connected at the bottom of the diaphragm. The natural frequency of the structure by LEM method is approximately 16.6 kHz which is closely matching with that of simulated structure with suitable approximations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20sensor" title="acoustic sensor">acoustic sensor</a>, <a href="https://publications.waset.org/abstracts/search?q=diaphragm%20based" title=" diaphragm based"> diaphragm based</a>, <a href="https://publications.waset.org/abstracts/search?q=lumped%20element%20modeling%20%28LEM%29" title=" lumped element modeling (LEM)"> lumped element modeling (LEM)</a>, <a href="https://publications.waset.org/abstracts/search?q=natural%20frequency" title=" natural frequency"> natural frequency</a>, <a href="https://publications.waset.org/abstracts/search?q=piezoelectric" title=" piezoelectric"> piezoelectric</a> </p> <a href="https://publications.waset.org/abstracts/87746/modeling-of-microelectromechanical-systems-diaphragm-based-acoustic-sensor" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/87746.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">448</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1775</span> Analysis of Joint Source Channel LDPC Coding for Correlated Sources Transmission over Noisy Channels</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Marwa%20Ben%20Abdessalem">Marwa Ben Abdessalem</a>, <a href="https://publications.waset.org/abstracts/search?q=Amin%20Zribi"> Amin Zribi</a>, <a href="https://publications.waset.org/abstracts/search?q=Ammar%20Bouall%C3%A8gue"> Ammar Bouallègue</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, a Joint Source Channel coding scheme based on LDPC codes is investigated. We consider two concatenated LDPC codes, one allows to compress a correlated source and the second to protect it against channel degradations. The original information can be reconstructed at the receiver by a joint decoder, where the source decoder and the channel decoder run in parallel by transferring extrinsic information. We investigate the performance of the JSC LDPC code in terms of Bit-Error Rate (BER) in the case of transmission over an Additive White Gaussian Noise (AWGN) channel, and for different source and channel rate parameters. We emphasize how JSC LDPC presents a performance tradeoff depending on the channel state and on the source correlation. We show that, the JSC LDPC is an efficient solution for a relatively low Signal-to-Noise Ratio (SNR) channel, especially with highly correlated sources. Finally, a source-channel rate optimization has to be applied to guarantee the best JSC LDPC system performance for a given channel. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=AWGN%20channel" title="AWGN channel">AWGN channel</a>, <a href="https://publications.waset.org/abstracts/search?q=belief%20propagation" title=" belief propagation"> belief propagation</a>, <a href="https://publications.waset.org/abstracts/search?q=joint%20source%20channel%20coding" title=" joint source channel coding"> joint source channel coding</a>, <a href="https://publications.waset.org/abstracts/search?q=LDPC%20codes" title=" LDPC codes"> LDPC codes</a> </p> <a href="https://publications.waset.org/abstracts/62721/analysis-of-joint-source-channel-ldpc-coding-for-correlated-sources-transmission-over-noisy-channels" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/62721.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">362</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1774</span> Unequal Error Protection of VQ Image Transmission System </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Khelifi%20Mustapha">Khelifi Mustapha</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Moulay%20lakhdar"> A. Moulay lakhdar</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20Elawady"> I. Elawady </a> </p> <p class="card-text"><strong>Abstract:</strong></p> We will study the unequal error protection for VQ image. We have used the Reed Solomon (RS) Codes as Channel coding because they offer better performance in terms of channel error correction over a binary output channel. One such channel (binary input and output) should be considered if it is the case of the application layer, because it includes all the features of the layers located below and on the what it is usually not feasible to make changes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=vector%20quantization" title="vector quantization">vector quantization</a>, <a href="https://publications.waset.org/abstracts/search?q=channel%20error%20correction" title=" channel error correction"> channel error correction</a>, <a href="https://publications.waset.org/abstracts/search?q=Reed-Solomon%20channel%20coding" title=" Reed-Solomon channel coding"> Reed-Solomon channel coding</a>, <a href="https://publications.waset.org/abstracts/search?q=application" title=" application"> application</a> </p> <a href="https://publications.waset.org/abstracts/21372/unequal-error-protection-of-vq-image-transmission-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21372.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">370</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1773</span> Sound Performance of a Composite Acoustic Coating With Embedded Parallel Plates Under Hydrostatic Pressure</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bo%20Hu">Bo Hu</a>, <a href="https://publications.waset.org/abstracts/search?q=Shibo%20Wang"> Shibo Wang</a>, <a href="https://publications.waset.org/abstracts/search?q=Haoyang%20Zhang"> Haoyang Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Jie%20Shi"> Jie Shi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> With the development of sonar detection technology, the acoustic stealth technology of underwater vehicles is facing severe challenges. The underwater acoustic coating is developing towards the direction of low-frequency absorption capability and broad absorption frequency bandwidth. In this paper, an acoustic model of underwater acoustic coating of composite material embedded with periodical steel structure is presented. The model has multiple high absorption peaks in the frequency range of 1kHz-8kHz, where achieves high sound absorption and broad bandwidth performance. It is found that the frequencies of the absorption peaks are related to the classic half-wavelength transmission principle. The sound absorption performance of the acoustic model is investigated by the finite element method using COMSOL software. The sound absorption mechanism of the proposed model is explained by the distributions of the displacement vector field. The influence of geometric parameters of periodical steel structure, including thickness and distance, on the sound absorption ability of the proposed model are further discussed. The acoustic model proposed in this study provides an idea for the design of underwater low-frequency broadband acoustic coating, and the results shows the possibility and feasibility for practical underwater application. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20coating" title="acoustic coating">acoustic coating</a>, <a href="https://publications.waset.org/abstracts/search?q=composite%20material" title=" composite material"> composite material</a>, <a href="https://publications.waset.org/abstracts/search?q=broad%20frequency%20bandwidth" title=" broad frequency bandwidth"> broad frequency bandwidth</a>, <a href="https://publications.waset.org/abstracts/search?q=sound%20absorption%20performance" title=" sound absorption performance"> sound absorption performance</a> </p> <a href="https://publications.waset.org/abstracts/167774/sound-performance-of-a-composite-acoustic-coating-with-embedded-parallel-plates-under-hydrostatic-pressure" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/167774.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">179</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1772</span> Comparison Analysis of Multi-Channel Echo Cancellation Using Adaptive Filters</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sahar%20Mobeen">Sahar Mobeen</a>, <a href="https://publications.waset.org/abstracts/search?q=Anam%20Rafique"> Anam Rafique</a>, <a href="https://publications.waset.org/abstracts/search?q=Irum%20Baig"> Irum Baig</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Acoustic echo cancellation in multichannel is a system identification application. In real time environment, signal changes very rapidly which required adaptive algorithms such as Least Mean Square (LMS), Leaky Least Mean Square (LLMS), Normalized Least Mean square (NLMS) and average (AFA) having high convergence rate and stable. LMS and NLMS are widely used adaptive algorithm due to less computational complexity and AFA used of its high convergence rate. This research is based on comparison of acoustic echo (generated in a room) cancellation thorough LMS, LLMS, NLMS, AFA and newly proposed average normalized leaky least mean square (ANLLMS) adaptive filters. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=LMS" title="LMS">LMS</a>, <a href="https://publications.waset.org/abstracts/search?q=LLMS" title=" LLMS"> LLMS</a>, <a href="https://publications.waset.org/abstracts/search?q=NLMS" title=" NLMS"> NLMS</a>, <a href="https://publications.waset.org/abstracts/search?q=AFA" title=" AFA"> AFA</a>, <a href="https://publications.waset.org/abstracts/search?q=ANLLMS" title=" ANLLMS"> ANLLMS</a> </p> <a href="https://publications.waset.org/abstracts/28829/comparison-analysis-of-multi-channel-echo-cancellation-using-adaptive-filters" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/28829.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">573</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1771</span> Personal Perception of the Acoustic Properties of Three Different Rooms for Music Lessons</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Natalia%20Ivanova">Natalia Ivanova</a>, <a href="https://publications.waset.org/abstracts/search?q=Konstantin%20Adamov"> Konstantin Adamov</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The importance of acoustics in music classes made us analyse three music rooms in a Bulgarian school. The same music piece was performed in every one of the classrooms. The recording was played to 2 groups of students. A survey was then taken among those students in order to determine their personal preferences and impressions of the acoustic. The results show differences in the preferences of older students compared to younger ones. Results of the survey show a correlation between older students’ preferences and the standard requirements. However, we discover that younger students’ classrooms should be further analysed and adapted to their needs and preferences. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acousic" title="acousic">acousic</a>, <a href="https://publications.waset.org/abstracts/search?q=building%20acoustic" title=" building acoustic"> building acoustic</a>, <a href="https://publications.waset.org/abstracts/search?q=sound%20quality" title=" sound quality"> sound quality</a>, <a href="https://publications.waset.org/abstracts/search?q=scool%20acoustic" title=" scool acoustic"> scool acoustic</a> </p> <a href="https://publications.waset.org/abstracts/157391/personal-perception-of-the-acoustic-properties-of-three-different-rooms-for-music-lessons" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/157391.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">109</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1770</span> Acoustic Modeling of a Data Center with a Hot Aisle Containment System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Arshad%20Alfoqaha">Arshad Alfoqaha</a>, <a href="https://publications.waset.org/abstracts/search?q=Seth%20Bard"> Seth Bard</a>, <a href="https://publications.waset.org/abstracts/search?q=Dustin%20Demetriou"> Dustin Demetriou</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A new multi-physics acoustic modeling approach using ANSYS Mechanical FEA and FLUENT CFD methods is developed for modeling servers mounted to racks, such as IBM Z and IBM Power Systems, in data centers. This new approach allows users to determine the thermal and acoustic conditions that people are exposed to within the data center. The sound pressure level (SPL) exposure for a human working inside a hot aisle containment system inside the data center is studied. The SPL is analyzed at the noise source, at the human body, on the rack walls, on the containment walls, and on the ceiling and flooring plenum walls. In the acoustic CFD simulation, it is assumed that a four-inch diameter sphere with monopole acoustic radiation, placed in the middle of each rack, provides a single-source representation of all noise sources within the rack. Ffowcs Williams & Hawkings (FWH) acoustic model is employed. The target frequency is 1000 Hz, and the total simulation time for the transient analysis is 1.4 seconds, with a very small time step of 3e-5 seconds and 10 iterations to ensure convergence and accuracy. A User Defined Function (UDF) is developed to accurately simulate the acoustic noise source, and a Dynamic Mesh is applied to ensure acoustic wave propagation. Initial validation of the acoustic CFD simulation using a closed-form solution for the spherical propagation of an acoustic point source is performed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=data%20centers" title="data centers">data centers</a>, <a href="https://publications.waset.org/abstracts/search?q=FLUENT" title=" FLUENT"> FLUENT</a>, <a href="https://publications.waset.org/abstracts/search?q=acoustics" title=" acoustics"> acoustics</a>, <a href="https://publications.waset.org/abstracts/search?q=sound%20pressure%20level" title=" sound pressure level"> sound pressure level</a>, <a href="https://publications.waset.org/abstracts/search?q=SPL" title=" SPL"> SPL</a>, <a href="https://publications.waset.org/abstracts/search?q=hot%20aisle%20containment" title=" hot aisle containment"> hot aisle containment</a>, <a href="https://publications.waset.org/abstracts/search?q=IBM" title=" IBM"> IBM</a> </p> <a href="https://publications.waset.org/abstracts/141377/acoustic-modeling-of-a-data-center-with-a-hot-aisle-containment-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/141377.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">182</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1769</span> Numerical Simulation of Effect of Various Rib Configurations on Enhancing Heat Transfer of Matrix Cooling Channel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seok%20Min%20Choi">Seok Min Choi</a>, <a href="https://publications.waset.org/abstracts/search?q=Minho%20Bang"> Minho Bang</a>, <a href="https://publications.waset.org/abstracts/search?q=Seuong%20Yun%20Kim"> Seuong Yun Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=Hyungmin%20Lee"> Hyungmin Lee</a>, <a href="https://publications.waset.org/abstracts/search?q=Won-Gu%20Joo"> Won-Gu Joo</a>, <a href="https://publications.waset.org/abstracts/search?q=Hyung%20Hee%20Cho"> Hyung Hee Cho</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The matrix cooling channel was used for gas turbine blade cooling passage. The matrix cooling structure is useful for the structure stability however the cooling performance of internal cooling channel was not enough for cooling. Therefore, we designed the rib configurations in the matrix cooling channel to enhance the cooling performance. The numerical simulation was conducted to analyze cooling performance of rib configured matrix cooling channel. Three different rib configurations were used which are vertical rib, angled rib and c-type rib. Three configurations were adopted in two positions of matrix cooling channel which is one fourth and three fourth of channel. The result shows that downstream rib has much higher cooling performance than upstream rib. Furthermore, the angled rib in the channel has much higher cooling performance than vertical rib. This is because; the angled rib improves the swirl effect of matrix cooling channel more effectively. The friction factor was increased with the installation of rib. However, the thermal performance was increased with the installation of rib in the matrix cooling channel. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=matrix%20cooling" title="matrix cooling">matrix cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=rib" title=" rib"> rib</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20transfer" title=" heat transfer"> heat transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=gas%20turbine" title=" gas turbine"> gas turbine</a> </p> <a href="https://publications.waset.org/abstracts/80524/numerical-simulation-of-effect-of-various-rib-configurations-on-enhancing-heat-transfer-of-matrix-cooling-channel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/80524.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">466</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1768</span> Influence of Bragg Reflectors Pairs on Resonance Characteristics of Solidly Mounted Resonators</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Vinita%20Choudhary">Vinita Choudhary</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The solidly mounted resonator (SMR) is a bulk acoustic wave-based device consisting of a piezoelectric layer sandwiched between two electrodes upon Bragg reflectors, which then are attached to a substrate. To transform the effective acoustic impedance of the substrate to a near zero value, the Bragg reflectors are composed of alternating high and low acoustic impedance layers of quarter-wavelength thickness. In this work presents the design and investigation of acoustic Bragg reflectors (ABRs) for solidly mounted bulk acoustic wave resonators through analysis and simulation. This performance of the resonator is analyzed using 1D Mason modeling. The performance parameters are the effect of Bragg pairs number on transmissivity, reflectivity, insertion loss, the electromechanical and quality factor of the 5GHz operating resonator. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bragg%20reflectors" title="bragg reflectors">bragg reflectors</a>, <a href="https://publications.waset.org/abstracts/search?q=SMR" title=" SMR"> SMR</a>, <a href="https://publications.waset.org/abstracts/search?q=insertion%20loss" title=" insertion loss"> insertion loss</a>, <a href="https://publications.waset.org/abstracts/search?q=quality%20factor" title=" quality factor"> quality factor</a> </p> <a href="https://publications.waset.org/abstracts/164288/influence-of-bragg-reflectors-pairs-on-resonance-characteristics-of-solidly-mounted-resonators" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/164288.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">109</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1767</span> Bearing Condition Monitoring with Acoustic Emission Techniques</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Faisal%20AlShammari">Faisal AlShammari</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdulmajid%20Addali"> Abdulmajid Addali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Monitoring the conditions of rotating machinery as bearing is important in order to improve its stability of works. Acoustic emission (AE) and vibration analysis are some of the most accomplished techniques used for this purpose. Acoustic emission has the ability to detect the initial phase of component degradation. Moreover, it has been observed that the success of vibration analysis does not take place below 100 rpm rotational speed. This because the energy generated below 100 rpm rotational speed is not detectable using conventional vibration. From this pint, this paper has presented a focused review of using acoustic emission techniques for monitoring bearings condition. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=condition%20monitoring" title="condition monitoring">condition monitoring</a>, <a href="https://publications.waset.org/abstracts/search?q=stress%20wave%20analysis" title=" stress wave analysis"> stress wave analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=low-speed%20bearings" title=" low-speed bearings"> low-speed bearings</a>, <a href="https://publications.waset.org/abstracts/search?q=bearing%20defect%20diagnosis" title=" bearing defect diagnosis"> bearing defect diagnosis</a> </p> <a href="https://publications.waset.org/abstracts/40780/bearing-condition-monitoring-with-acoustic-emission-techniques" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/40780.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">320</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1766</span> Turbulence Measurement Over Rough and Smooth Bed in Open Channel Flow</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kirti%20Singh">Kirti Singh</a>, <a href="https://publications.waset.org/abstracts/search?q=Kesheo%20Prasad"> Kesheo Prasad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A 3D Acoustic Doppler velocimeter was used in the current investigation to quantify the mean and turbulence characteristics in non-uniform open-channel flows. Results are obtained from studies done in the laboratory, analysing the behavior of sand particles under turbulent open channel flow conditions flowing through rough, porous beds. Data obtained from ADV is used to calculate turbulent flow characteristics, Reynolds stresses and turbulent kinetic energy. Theoretical formulations for the distribution of Reynolds stress and the vertical velocity have been constructed using the Reynolds equation and the continuity equation of 2D open-channel flow. The measured Reynolds stress profile and the vertical velocity are comparable with the derived expressions. This study uses the Navier-Stokes equations for analysing the behavior of the vertical velocity profile in the dominant region of full-fledged turbulent flows in open channels, and it gives a new origination of the profile. For both wide and narrow open channels, this origination can estimate the time-averaged primary velocity in the turbulent boundary layer's outer region. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=turbulence" title="turbulence">turbulence</a>, <a href="https://publications.waset.org/abstracts/search?q=bed%20roughness" title=" bed roughness"> bed roughness</a>, <a href="https://publications.waset.org/abstracts/search?q=logarithmic%20law" title=" logarithmic law"> logarithmic law</a>, <a href="https://publications.waset.org/abstracts/search?q=shear%20stress%20correlations" title=" shear stress correlations"> shear stress correlations</a>, <a href="https://publications.waset.org/abstracts/search?q=ADV" title=" ADV"> ADV</a>, <a href="https://publications.waset.org/abstracts/search?q=Reynolds%20shear%20stress" title=" Reynolds shear stress"> Reynolds shear stress</a> </p> <a href="https://publications.waset.org/abstracts/159300/turbulence-measurement-over-rough-and-smooth-bed-in-open-channel-flow" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/159300.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">116</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1765</span> Investigation of the Acoustic Properties of Recycled Felt Panels and Their Application in Classrooms and Multi-Purpose Halls</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ivanova%20B.%20Natalia">Ivanova B. Natalia</a>, <a href="https://publications.waset.org/abstracts/search?q=Djambova%20%D0%A2.%20Svetlana"> Djambova Т. Svetlana</a>, <a href="https://publications.waset.org/abstracts/search?q=Hristev%20S.%20Ivailo"> Hristev S. Ivailo</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The acoustic properties of recycled felt panels have been investigated using various methods. Experimentally, the sound insulation of the panels has been evaluated for frequencies in the range of 600 Hz to 4000 Hz, utilizing a small-sized acoustic chamber. Additionally, the sound absorption coefficient for the frequency range of 63 Hz to 4000 Hz was measured according to the EN ISO 354 standard in a laboratory reverberation room. This research was deemed necessary after conducting reverberation time measurements of a university classroom following the EN ISO 3382-2 standard. The measurements indicated values of 2.86 s at 500 Hz, 3.23 s at 1000 Hz, and 2.53 s at 2000 Hz, which significantly exceeded the requirements set by the national regulatory framework (0.6s) for such premises. For this reason, recycled felt panels have been investigated in the laboratory, showing very good acoustic properties at high frequencies. To enhance performance in the low frequencies, the influence of the distance of the panel spacing was examined. Furthermore, the sound insulation of the panels was studied to expand the possibilities of their application, both for the acoustic treatment of educational and multifunctional halls and for sound insulation purposes (e.g., a suspended ceiling with an air gap passing from room to room). As a conclusion, a theoretical acoustic design of the classroom has been carried out with suggestions for improvements to achieve the necessary acoustic and aesthetic parameters for such rooms. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20panels" title="acoustic panels">acoustic panels</a>, <a href="https://publications.waset.org/abstracts/search?q=recycled%20felt" title=" recycled felt"> recycled felt</a>, <a href="https://publications.waset.org/abstracts/search?q=sound%20absorption" title=" sound absorption"> sound absorption</a>, <a href="https://publications.waset.org/abstracts/search?q=sound%20insulation" title=" sound insulation"> sound insulation</a>, <a href="https://publications.waset.org/abstracts/search?q=classroom%20acoustics" title=" classroom acoustics"> classroom acoustics</a> </p> <a href="https://publications.waset.org/abstracts/167058/investigation-of-the-acoustic-properties-of-recycled-felt-panels-and-their-application-in-classrooms-and-multi-purpose-halls" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/167058.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">95</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1764</span> Adaptive Transmission Scheme Based on Channel State in Dual-Hop System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Seung-Jun%20Yu">Seung-Jun Yu</a>, <a href="https://publications.waset.org/abstracts/search?q=Yong-Jun%20Kim"> Yong-Jun Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=Jung-In%20Baik"> Jung-In Baik</a>, <a href="https://publications.waset.org/abstracts/search?q=Hyoung-Kyu%20Song"> Hyoung-Kyu Song</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, a dual-hop relay based on channel state is studied. In the conventional relay scheme, a relay uses the same modulation method without reference to channel state. But, a relay uses an adaptive modulation method with reference to channel state. If the channel state is poor, a relay eliminates latter 2 bits and uses Quadrature Phase Shift Keying (QPSK) modulation. If channel state is good, a relay modulates the received symbols with 16-QAM symbols by using 4 bits. The performance of the proposed scheme for Symbol Error Rate (SER) and throughput is analyzed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=adaptive%20transmission" title="adaptive transmission">adaptive transmission</a>, <a href="https://publications.waset.org/abstracts/search?q=channel%20state" title=" channel state"> channel state</a>, <a href="https://publications.waset.org/abstracts/search?q=dual-hop" title=" dual-hop"> dual-hop</a>, <a href="https://publications.waset.org/abstracts/search?q=hierarchical%20modulation" title=" hierarchical modulation"> hierarchical modulation</a>, <a href="https://publications.waset.org/abstracts/search?q=relay" title=" relay"> relay</a> </p> <a href="https://publications.waset.org/abstracts/52599/adaptive-transmission-scheme-based-on-channel-state-in-dual-hop-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/52599.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">385</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1763</span> Formation of Round Channel for Microfluidic Applications</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=A.%20Zahra">A. Zahra</a>, <a href="https://publications.waset.org/abstracts/search?q=G.%20de%20Cesare"> G. de Cesare</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20Caputo"> D. Caputo</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Nascetti"> A. Nascetti</a> </p> <p class="card-text"><strong>Abstract:</strong></p> PDMS (Polydimethylsiloxane) polymer is a suitable material for biological and MEMS (Microelectromechanical systems) designers, because of its biocompatibility, transparency and high resistance under plasma treatment. PDMS round channel is always been of great interest due to its ability to confine the liquid with membrane type micro valves. In this paper we are presenting a very simple way to form round shape microfluidic channel, which is based on reflow of positive photoresist AZ® 40 XT. With this method, it is possible to obtain channel of different height simply by varying the spin coating parameters of photoresist. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=lab-on-chip" title="lab-on-chip">lab-on-chip</a>, <a href="https://publications.waset.org/abstracts/search?q=PDMS" title=" PDMS"> PDMS</a>, <a href="https://publications.waset.org/abstracts/search?q=reflow" title=" reflow"> reflow</a>, <a href="https://publications.waset.org/abstracts/search?q=round%20microfluidic%20channel" title=" round microfluidic channel"> round microfluidic channel</a> </p> <a href="https://publications.waset.org/abstracts/7886/formation-of-round-channel-for-microfluidic-applications" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7886.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">438</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">1762</span> Design of an Acoustic Imaging Sensor Array for Mobile Robots</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dibyendu%20Roy">Dibyendu Roy</a>, <a href="https://publications.waset.org/abstracts/search?q=V.%20Ramu%20Reddy"> V. Ramu Reddy</a>, <a href="https://publications.waset.org/abstracts/search?q=Parijat%20Deshpande"> Parijat Deshpande</a>, <a href="https://publications.waset.org/abstracts/search?q=Ranjan%20Dasgupta"> Ranjan Dasgupta</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Imaging of underwater objects is primarily conducted by acoustic imagery due to the severe attenuation of electro-magnetic waves in water. Acoustic imagery underwater has varied range of significant applications such as side-scan sonar, mine hunting sonar. It also finds utility in other domains such as imaging of body tissues via ultrasonography and non-destructive testing of objects. In this paper, we explore the feasibility of using active acoustic imagery in air and simulate phased array beamforming techniques available in literature for various array designs to achieve a suitable acoustic sensor array design for a portable mobile robot which can be applied to detect the presence/absence of anomalous objects in a room. The multi-path reflection effects especially in enclosed rooms and environmental noise factors are currently not simulated and will be dealt with during the experimental phase. The related hardware is designed with the same feasibility criterion that the developed system needs to be deployed on a portable mobile robot. There is a trade of between image resolution and range with the array size, number of elements and the imaging frequency and has to be iteratively simulated to achieve the desired acoustic sensor array design. The designed acoustic imaging array system is to be mounted on a portable mobile robot and targeted for use in surveillance missions for intruder alerts and imaging objects during dark and smoky scenarios where conventional optic based systems do not function well. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=acoustic%20sensor%20array" title="acoustic sensor array">acoustic sensor array</a>, <a href="https://publications.waset.org/abstracts/search?q=acoustic%20imagery" title=" acoustic imagery"> acoustic imagery</a>, <a href="https://publications.waset.org/abstracts/search?q=anomaly%20detection" title=" anomaly detection"> anomaly detection</a>, <a href="https://publications.waset.org/abstracts/search?q=phased%20array%20beamforming" title=" phased array beamforming"> phased array beamforming</a> </p> <a href="https://publications.waset.org/abstracts/43887/design-of-an-acoustic-imaging-sensor-array-for-mobile-robots" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/43887.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">415</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=acoustic%20channel&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=acoustic%20channel&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=acoustic%20channel&page=4">4</a></li> <li class="page-item"><a class="page-link" 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