bluuebunny/crossref_metadata_2025 huggingface dataset:
Ex vivo mechanical testing of various suture patterns for use in tendon plating
Authors: Hale Michael J. , Zellner Eric M. , Naiman Jaron H. , Kraus Karl H.
Published: June 2021

Objective

To determine the influence of suture patterns on resistance to gap formation after tendon plating

Study Design

Ex vivo study

Sample Population

Suspensory ligament and superficial and deep digital flexor tendons harvested from 16 neonatal cadaver foal limbs.

Methods

Each tendon/ligament from a given limb was randomly assigned to one of three treatment groups consisting of a 7‐hole veterinary cuttable plate fixed with alternating simple interrupted, figure‐8, or hybrid suture patterns. The constructs were distracted at a rate of 1.0 mm/s to failure, as determined by the formation of a 1 mm gap for initial failure and a 3 mm gap for ultimate failure. The mode of failure was also recorded.

Results

Constructs prepared with hybrid and figure‐8 patterns sustained over 2× higher (p < .01) forces before gap formation compared to those prepared with a simple interrupted pattern. No difference was identified between tendons whose plate was secured with hybrid or figure‐8 suture patterns. Mode of failure between groups did not differ.

Conclusion

The figure‐8 and hybrid patterns described herein improved the resistance to gap formation of plated tendons compared to an alternating simple interrupted pattern described previously.

Clinical Significance

Figure‐8 and hybrid patterns should be considered over simple interrupted patterns to improve resistance to gap formation in horses undergoing tendon plating.
Development of FEA-ANN-Integrated Approach for Process Optimization of Coaxial One-Side Resistance Spot Welding of Al5052 and CFRP
Authors: Ren Sendong , Ma Yunwu , Ma Ninshu
Published: June 2021

Coaxial one-side resistance spot welding (COS-RSW) is a newly developed process for joining metals and composites. In the present study, Al5052 and carbon-fiber-reinforced plastic (CFRP) lap joints were fabricated via COS-RSW. The welding process was modeled numerically using an in-house finite element code called JWRIAN. Single-lap shear tests were performed to evaluate the joining strength. The molten zone diameter was defined and measured experimentally to verify the numerical model. An artificial neural network (ANN) was established based on multitask learning, and its training data set was prepared via finite element analysis (FEA). The well-trained ANN was employed to generate a process window for the COS-RSW. Results demonstrated that the FEA could accurately reproduce the COS-RSW process, which served as an efficient tool for generating a process data set without performing experiments. The ANN performed multitask learning well and predicted the welding output effectively. Furthermore, Tmavg, an index representing the average value of the maximum temperature in the molten interface of CFRP, was adopted to evaluate the contribution of the integral interface temperature field to the bonding strength qualitatively. An optimal Tmavg value, which was close to the CFRP decomposition temperature of 340 °C, was obtained, and it exhibited an excellent correlation with higher bonding strengths. The process window provided welding parameters directly to yield the desired results.
Modeling of Robot's Low-Speed Motion Nonlinear Dynamics Based on Phase Space Reconstruction Neural Network
Authors: Zhang Tie , Liang Xiaohong , Zou Yanbiao
Published: June 2021

In order to improve the accuracy of the robot dynamics model, a low-speed motion nonlinear dynamics modeling method of industrial robot based on phase space reconstruction neural network is proposed. It is confirmed in advance by the largest Lyapunov exponent of joint motor torque data that the robot has chaotic characteristics at low-speed motion. Therefore, experimental data and chaos theory is used to analyze low-speed motion nonlinear dynamics, instead of considering each factor that may cause the robot's nonlinear dynamics separately. The phase space reconstruction parameters of each joint are determined by autocorrelation method and false nearest neighbor method. Through data preprocessing and analysis, some joint position derivatives related to the changing law of torque data are determined. The phase space reconstruction values of these derivatives are chosen as the inputs of neural network. Then the neural network and curve fitting method are combined to compensate for the nonlinear joint torque. Experimental results show that the proposed method can better describe the robot's low-speed motion nonlinear dynamics, and has smaller errors compared with ordinary back propagation (BP) neural network in the case of single joint rotation.
Experimental oscillation-assisted cylindrical plunge grinding
Authors: Pawlowski Witold , Kepczak Norbert , Bechcinski Grzegorz , Sikorski Jakub
Published: June 2021

The paper presents experimental studies of the influence of amplitude, frequency, time of oscillation and average value of the rotational speed of the workpiece on the waviness of the ground surface during cylindrical outer diameter plunge grinding on a mass-produced cylindrical grinder. Oscillations were introduced in order to counteract the development of self-excited vibrations during spark-out. The waviness of the surface was determined by a laser distance measurement system. The results of the experiments indicate the important positive influence of the oscillations applied during spark-out on the waviness of the ground surface. The conclusions of the study regarding the process as well as technology of cylindrical plunge grinding are presented.
Automated Geometric Correction System for Additive Manufacturing Considering Build Orientation
Authors: Ghiasian Seyedeh Elaheh , Lewis Kemper
Published: June 2021

One of the current challenges for the additive manufacturing (AM) industry lies in providing component designs compatible with the AM manufacturability and constraints without compromising the component structural functionalities. To address this challenge, we present an automated correction system that provides geometrically feasible designs for additive processes by applying locally effective modifications while avoiding substantial changes in the current designs. Considering a minimum printable feature size from the process parameters, this system identifies the problematic features in an infeasible part’s design using a holistic geometric assessment algorithm. Based on the obtained manufacturability feedback, the system then corrects the detected problematic regions using a set of appropriate redesign solutions through an automated procedure. In addition, to reduce the difference between the current and modified part geometries, a novel optimization model for build orientation is presented. By using this model, one can identify appropriate orientations for obtaining a feasible design with a minimal amount of corrections while also reducing the postprocessing effort by minimizing the area of contact with the support structure. The functionalities of the presented correction system and the optimization model are illustrated using a number of case studies with varying geometries. The computational performance of the system and an experimental validation are also presented to demonstrate the effectiveness of the implemented detection and modification approaches.
Wireless Multiplexing Control Based on Magnetic Coupling Resonance and Its Applications in Robot
Authors: Wang Jue , Chen Genliang , Zhang Zhuang , Suo Jiaqi , Wang Hao
Published: June 2021

Nowadays, more and more researchers are pursuing miniaturized and lightweight structure of robots. However, robots with multiple actuators require large control systems if each actuator needs to be controlled independently. In addition, the cables and circuits for control and power supply are the obstacles in reducing size and weight. In this article, a wireless multiplexing control system based on magnetic coupling resonance (MCR) is proposed. The control system can realize wireless energy transmission and control simultaneously. By decomposing a composite signal, it can control multiple actuators with only one input signal. However, in previous researches, their applications are primary and simple due to the switch control without feedback and the lack of systematic design method for robot application. Thus, based on the discrete form of composite signal, the closed-loop of wireless multiplexing control is presented, which makes this promising method a step closer to the practical application. Besides, based on the theoretical model of load power and transmission efficiency, five parameters to be optimized are extracted in accordance with the actual design requirements. The optimization algorithm for load power is proposed using particle swarm optimization (PSO). As for its applications in robots, a Delta robot with flexible linkage and an untethered multidrive pipe robot for sampling operation are designed to demonstrate the proposed control method. The experiment results of the Delta robot show the reliability and accuracy of the system, while the results of the pipe robot prove its potential use in the untethered robot system.
Co-Simulation and Control of a Single-Wheel Pendulum Mobile Robot
Authors: Herrera-Cordero Mario E. , Arias-Montiel Manuel , Ceccarelli Marco , Lugo-Gonzalez Esther
Published: June 2021

Co-simulation is widely used as a powerful tool for performance evaluation of systems design. This approach presents advantages over traditional design methodologies for saving money and time in the development process and the possibility of evaluating rapidly design alternatives by using virtual prototypes. This article presents an ADAMS/Matlab co-simulation for the dynamics and control of a Single-Wheel pendulum ROBot (SWROB) with inertial locomotion actuation to characterize design solutions by means of validation of analytical results. The obtained results by the proposed co-simulation show a significant performance based on the analytical and programming efforts in characterizing and simulating the designed system model. Moreover, open-loop experimental results are presented to validate both the analytical model and the virtual prototype.
On Robust Mechanical Design of a PAR2 Delta-Like Parallel Kinematic Manipulator
Authors: Brahmia Allaoua , Kelaiaia Ridha , Chemori Ahmed , Company Olivier
Published: June 2021

Sensitivity analysis of manipulators aims at studying the influence of variations in its own geometric parameters on its performance. This information is useful for evaluating the position error of the end-effector as well as for the synthesis of tolerances. Indeed, the synthesis of tolerances is a very important issue in the design and manufacturing of robot manipulators. In this paper, a sequential procedure for modeling, dimensioning, and tolerance synthesis of the Parallel Kinematic Manipulator (PKM) PAR2 is proposed. For optimal dimensional design, an approach based on the optimization of the workspace is proposed, taking into account several constraints, followed by a numerical matrix analysis-based deterministic method for sensitivity analysis whose performance is studied in terms of accuracy. To calculate the optimal dimensional tolerances, a new tolerance synthesis method is used. The effect of geometric tolerance on accuracy is analyzed.
Performance Enhancement Using Different Nitromethane Blends in a Small Two-Stroke Engine
Authors: Raviteja S. , Ramakrishna P. A. , Ramesh A.
Published: June 2021

Nitromethane being immiscible in gasoline is often added to methanol to enhance the engine power output. But with the use of methanol as the base fuel, the brake specific fuel consumption (BSFC) of the spark ignition (SI) engine often doubles due to its lower heating value. To constrain this increase to a marginal value, a tri-component fuel blend consisting of nitromethane-alcohol-gasoline was prepared and observed to be stable. Methanol, ethanol, and butanol were the chosen alcohols for the tests due to their popularity as alternate fuels for SI engines. Tests on a small (35cc) two-stroke SI engine revealed that the torque produced with the use of tri-component blends was comparable with nitromethane-methanol blend and was on an average 1.35 times higher than gasoline. However, the BSFC with the nitromethane-butanol-gasoline blend was 50% lower than nitromethane-methanol blend and was only 14% higher than gasoline. The emission analysis showed lower HC emissions with the tri-component blends proving the improved combustion efficiency due to better mixing of the fuel-air mixture. Combustion analysis showed the increased heat release rate with nitromethane addition due to its higher flame speeds.
Micro Gas Turbine Small-Scale Effects in Range Extended Electric Vehicles
Authors: Javed Adeel , Khalid Hassan Abdullah , Arif Syed Umer bin , Imran Muhammad , Rezk Ahmed , Khan Zafar Ali
Published: June 2021

Application of a range extender in an electric vehicle can reduce the battery bank size and extend the driving range on a need basis. A micro gas turbine offers high power density, fuel flexibility, a reliable thermal efficiency (with recuperation), and less raw exhaust gaseous emissions compared to an internal combustion engine. However, micro gas turbines also incur low component performances due to small-scale effects related to high viscous losses, heat transfer between hot and cold sections, and manufacturing and assembly constraints compared to their larger counterparts. In this paper, the micro gas turbine thermodynamic cycle has been designed in Gas Turbine Simulation Program (GSP) and evaluated in terms of the small-scale effects simultaneously with the battery bank energy and charging time analysis. The key objective is to demonstrate the effectiveness of a micro gas turbine in saving the weight of a range-extended electric vehicle while understanding the impact of small-scale effects on the battery bank energy and charging time. Results indicate that a relatively smaller 22-kWh battery bank can be utilized with prospects of cost-savings together with a 47-kW micro gas turbine range extender to achieve an average driving range of 100 km and a charging time of 30 min for the baseline electric vehicle. Furthermore, the compressor and turbine isentropic efficiencies are found to have a significant impact on the overall battery bank performance.
Broadband optimization of volumetric sound metadiffusers
Authors: Shah Neel , Amirkulova Feruza
Published: June 2021

Broadband volumetric sound metadiffusers are designed by using gradient-based optimization and by means of multiple scattering theory (MST) employed to evaluate the scattered pressure field by a uniform planar configuration of cylindrical scatterers. The method is illustrated by giving numerical examples for planar configurations of rigid cylinders and thin elastic cylindrical shells situated in the air medium. By rearranging the position of each cylinder, a metadiffuser is optimized to have a high diffusion coefficient. Multiple scenarios are evaluated considering a single frequency and broadband optimization. Single frequency optimization is performed to optimize a configuration of cylinders at a specific wavenumber. Broadband optimization is used to optimize a cylinder configuration for a range of wavenumbers by optimizing the root mean square of diffusion coefficient evaluated at discreet values of normalized wavenumber. MATLAB MultiStart solver combined with parallel computing along with global optimization toolboxes is used to enhance the modeling for optimizing for both scenarios due to its ability to evaluate multiple starting points in parallel, hence being able to find the global optimum. A wide array of metadiffusers is optimized using MATLAB MultiStart and fmincon solvers with the sequential quadratic programming and genetic algorithm for a comparison of performance of these algorithms.
Impact of low sonic boom exposure on psychophysical and cognitive performance
Authors: Marmel Frédéric , Cretagne Léo , Thuong Linh-Thao , Coulouvrat Francois , Fritz Claudia
Published: June 2021

The RUMBLE project aimed to quantify the effects of low sonic boom exposure on human responses, in situations representative of the daily life of European citizens, so as to inform policy, establish standards and develop protection concepts for a new generation of supersonic commercial aircraft that should emit a reduced but perceivable boom (a “low boom”) while flying overland. Two low boom simulators were affixed to the bedrooms’ windows of a house located on our university campus. The simulators allowed us to study indoor the participants’ responses to realistic “outdoor” booms. Testing took place in both the living room and kitchen because the booms caused different intensities of rattle noise in those two rooms. Participants performed a communication task, a working memory task, a drawing task, and an automatic evaluation task. They also had three mandatory rests. We used questionnaires to assess the booms’ perception and annoyance as well as their influence on participants’ mood. The booms were rated unpleasant, especially with rattle, and more disturbing during the rests than during the tasks. The booms made the rests less relaxing and impaired short-term cognitive performance. [This research was conducted as a part of Rumble—EU Grant Agreement 769896.]
X-59 sonic boom demonstration performance
Authors: Morgenstern John
Published: June 2021

Lockheed Martin Aeronautics is building the X-59 Low Boom Flight Demonstrator (LBFD) for NASA’s quiet boom testing program. To determine the acceptability of quiet booms on (predominantly indoor) observers, the X-59 vehicle to designed to produce shaped booms representative of transports employing this technology. During a flight, the vehicle is designed for two steady, level passes between Mach 1.4 to 1.5, covering 50 nm in length and 30 + nm (std. day) in boom carpet width. Boom loudness from 75 to 90 PLdB can be selected for each pass by variations in Altitude, Mach or trimmed control deflections. Quieter boom from 70 to 75 PLdB can be produced in a gentle turn up to 8° degrees in bank angle. Phase 1 of the LBFD program covers design, fabrication, ground test and flight safety demonstration. The first wind tunnel boom test of a 19 in. X-59 model is planned for later this year. Beginning 2023, Phase 2 plans to validate the X-59 boom loudness with in-flight and ground measurements. Phase 3 plans to demonstrate varied quiet boom exposures at several sites in the USA.
Effect of listeners versus experimental factors in multi-talker speech segregation
Authors: Lutfi Robert A. , Rodriguez Briana , Lee Jungmee
Published: June 2021

Over six decades ago, Cherry (1953) drew attention to what he called the “cocktail-party problem”; the challenge of segregating the speech of one talker from others speaking at the same time. The problem has been actively researched ever since but, for all this time, one observation has alluded explanation. It is the wide variation in performance of individual listeners. That variation was replicated here for four major experimental factors known to impact performance: differences in task (talker segregation versus identification), differences in the voice features of talkers (pitch versus location), differences in the voice similarity and uncertainty of talkers and the presence or absence of linguistic cues. The effect of these factors on the segregation of naturally spoken sentences and synthesized vowels was largely eliminated in psychometric functions relating the performance of individual listeners to that of an ideal observer, d’ideal. The effect of listeners remained as differences in the slopes of the functions (fixed effect) with little within-listener variability in the estimates of slope (random effect). The results make a case for considering the listener a factor in multi-talker segregation equal in status to any major experimental variable. [Work supported by NIDCD R01 DC001262-27.]
On the acoustic black-hole effect in waveguides
Authors: Mousavi Abbas , Berggren Martin , Wadbro Eddie
Published: June 2021

The acoustic black-hole (ABH) effect is a well-known way of controlling structural vibrations in solid beams and plates. The theory behind this effect is to reduce the velocity of waves by altering the physical properties of the domain according to a power-law profile. For an ideal ABH, this leads to vanishing reflections from the end of the termination. In practice, there will be a truncation in the profile, which leads to some reflections. A well-known way of minimizing this truncation error is to add damping material to the end of the ABH termination. For a waveguide embedding a set of rings with retarding inner radius according to a power-law profile, the velocity of sound waves tends to zero. However, unlike the structural counterpart, experimental results in the literature show that adding damping material to reduce the truncation error is not effective for waveguides. Here, we present a finite element simulation of the considered cylindrical setup. Our results confirm that the addition of damping material to the end of the waveguide is ineffective while suggesting that the local absorption effects at the lateral surface of the cylinder are a primary source of damping to achieve the ABH effect.
Estimating the performance gap between lab and remote speech perception experiment
Authors: Cooke Martin , Garcia Lecumberri M. L.
Published: June 2021

The presentation will report on an online replication of several lab-based studies in the perception of masked, distorted and enhanced speech in which listener-related differences were controlled.
Recall of vowel sequences in altered rhythm contexts: In-person versus online testing
Authors: Pearson Dylan , Shen Yi , Kidd Gary R. , Devin McAuley J.
Published: June 2021

This presentation will outline the online replication of an in-lab vowel recall experiment to demonstrate the feasibility of conducting behavioral experiments that address high-level auditory processes through online-experiment platforms.
To touch or not to touch: Variations in mouse tracking across equipment profiles during online incidental learning of novel tone categories
Authors: Wright Jonathan , Baese-Berk Melissa
Published: June 2021

We measure mouse tracking during the incidental acquisition of novel tone categories, permitting a confusion matrix analysis of four novel tone categories. We present variations in mouse tracking response data that arise from inevitable differences in individual equipment profiles (e.g., touchpad, external mouse, etc.) as participants take the study online, rather than in a controlled environment.
A Bayesian active-learning test for remote hearing-aid fitting
Authors: Schlittenlacher Josef , Kluk Karolina , Stone Michael , Perugia Emanuele
Published: June 2021

A major problem of remote or online hearing tests is the calibration of the equipment and control of the acoustic environment: For example, an audiogram requires calibrated headphones with a wide dynamic range and a silent room. Instead, a notched-noise test alleviates these problems and gives valuable information about auditory filters that can be used to fit a hearing aid. Although absolute levels still play a role, relative levels between signal and noise are more robust as the environment does not need to be quieter than the noise. Using traditional methods, determination of auditory-filter shapes across the whole frequency range would take hours. We developed a notched-noise test that uses Gaussian Processes to maintain a probabilistic estimate of the outcome, and to select stimulus parameters based on mutual information. This active-learning method gives an estimate of auditory-filter shapes in about 30 minutes across a wide range of frequency. We demonstrate that these estimates, even when obtained with headphones for which the frequency response and exact calibration is unknown, are sufficient to give a good initial fit of a hearing aid.
Semi-supervised deep learning of source location and seabed class from unlabeled merchant ships in the shallow ocean
Authors: Acree Mason C. , Neilsen Tracianne B. , Knobles David P. , Hodgkiss William
Published: June 2021

Understanding sound propagation in a shallow ocean environment is complicated but important for naval technologies. Some researchers are currently applying a variety of supervised deep learning methods, such as convolution neural networks, for either source localization or seabed classification. One of the costs of supervised learning is the requirement for large amounts of labeled data. In the present study, unlabeled data are used to train a Transformer model. Transformer-based models have demonstrated ability for predicting sequential data; examples are Google’s BERT and OpenAI’s GPT-3. In our technique, we train a transformer-based model in a twopart process. First, self-supervised learning is implemented using synthetic ship spectrograms for various shallow ocean environments. The model is trained as an encoder/decoder to perform sequence-to-sequence prediction. Second, the transformer model is fine-tuned to predict the source location and seabed class from a small set of labeled synthetic samples. Data samples measured during the Seabed Characterization Experiment 2017 are utilized as a testing dataset. The advantages of this approach are the ability to train a model with a larger variety of data, including the use of unlabeled data and data of variable input length.
A substitution of convolutional layers by FFT layers—A low computational cost version
Authors: Mohammmad Umar Farooq , Wasih Mohammad , Almekkawy Mohamed
Published: June 2021

Convolutional Neural Networks (CNNs) have become recently a very common application of accurate diagnosis and early detection of liver abnormalities. CNN’s have very promising outputs and showed accurate results comparable to classical detection methods. However, one of their drawbacks is the exponential increase of the computational cost with the increase of the image size. We propose an upgraded neural network (NN) -based approach in which the convolution layers are replaced with Fast Fourier transform (FFT) Layers. Instead of the convolution of each pixel in a large ultrasound image with the kernel where the computational cost is of O(N2), we calculate the FFT of the image and the kernel separately and multiply them in the frequency domain where the computational cost is of O(N log N) and then calculate the inverse Fourier transform of the result. Accordingly, we have replaced the convolution with FFT for the forward and the backward propagation in the NN for the liver steatosis classification from ultrasound images of benign and malignant fatty liver. CNN layers resulted in 89.82% accuracy to classify 550 Ultrasound fatty liver images while our approach resulted in just a 4% reduction in the classification accuracy but with an 83.3% reduction in the computational time.
Ultrasound liver tumor segmentation with nested U-Net and dynamic feature extraction
Authors: Gao Qinhan , Almekkawy Mohamed
Published: June 2021

Locating tumor from ultrasound images is of high importance in medical analysis and diagnosis. There are mainly two challenges for segmenting tumors from ultrasound images. The first challenge is the low resolution and high speckle noise of ultrasound images. The second challenge is the various shapes and sizes of tumors. We propose a multi-level feature extraction neural network to automatically segment the data. Our purposed model is trained and tested with liver tumor ultrasound images from an open source dataset. Specifically, after pre-processing the dataset with median filter and data augmentation, we employ a collaborative model that utilizes nested U-net, U-Net + + as a backbone. The model is integrated with dense short skip connections within sub-networks to further improve the gradient flow and feature preservation. In addition, we modify the original atrous spacial pyramid to an adaptive pooling for better compatibility with nested U-Net. Adaptive atrous spacial pyramid pooling is designed to extract features from different levels and cover the increasing range of feature extraction with regard to the depth of the nested network. Segmentation results showed that the proposed model outperformed multiple network structures, and achieved a 0.915 3 dice coefficient, 0.843 8 intersection-over-union and 0.0019 mean square error.
Practitioner experience of coupled volume auditorium design
Authors: Wright Philip , Adams Paul , Nakajima Tateo , Brooks Todd , Bassuet Alban
Published: June 2021

This paper is written from the perspective of practitioners who approach the use of coupled volumes—in auditorium design in particular—as one element taken from a diverse acoustic design toolkit to be employed when appropriate to achieve an intended sound aesthetic conceived in response to the specific cultural setting of each space. In this approach, coupled volumes are considered part of a continuum of design options encompassing volumetric coupling effects and their inter-relationship with separation of early reflecting elements and room boundaries. The practice has experience with coupled volume design spanning a number of decades and from extensive listening and engagement with artists who have evolved through their experiences in these spaces. We describe particular insights gained as acoustics designers of the National Forum of Music concert hall in Wroclaw through our engagement from early strategic planning through initial operations relating to subjective and artistic preferences for set-up in performance across a varied repertoire. From a perspective spanning historical examples of coupled volume acoustics, through a consideration of auditorium design in recent history, we consider the place of coupled volume design in future.
On the acoustics of coupled volumes in the safavid architecture—Comparison of computer-modeled objective parameters of two historic buildings
Authors: Farzaneh Nima , Braasch Jonas
Published: June 2021

One of the typical architectural prototypes in the Safavid era is the utilization of nested rooms for creating assembly spaces with spatial connectivity. Varied in geometry and size, each volume contributes differently to the acoustical environment. Shah Mosque prayer hall and Ali Qapu Palace music room are the two rooms that employ this organization system in their planning. Various simulations have been performed on 3D models of these architectural entities to study the mechanism of sound energy exchange and the impact of each volume on the perceived acoustic characteristics. The objective parameters were collected for both rooms and compared in various configurations to understand each cluster of space's impact on the overall acoustic experience. Furthermore, materials' properties, proportions, and architectural features are discussed as contributing factors to the sonic landscape. The result shows that the sound energy decay behaves differently mainly due to the two rooms' differences in scale and sound absorptive properties. The comparative analysis verifies some of the previous research on coupled volumes in which these two precedents exhibit a similar non-exponentialsound energy decay.
Multi-cavity PLGA particles as a theranostic agent
Authors: Kwan James , Su Xiaoqian , Rakshit Moumita , Das Prativa , Gupta Ipshita , Das Dhiman , Pramanik Manojit , Woei Ng Kee
Published: June 2021

We have developed drug-loaded multi-cavity PLGA microparticles that act as both a cavitation nuclei and drug vehicle. Our work shows that these particle can be embedded into a tissue model, release a drug to reduce inflammation in a 3D cell culture model, and be imaged with B-mode ultrasound.
Sonothermogenetics for noninvasive and cell-type specific deep brain neuromodulation
Authors: Yang Yaoheng , Pham Pacia Christopher , Ye Dezhuang , Zhu Lifei , Baek Hongchae , Yue Yimei , Yuan Jinyun , Miller Mark J. , Cui Jianmin , Culver Joseph P. , Bruchas Michael R. , Chen Hong
Published: June 2021

This study aimed to develop sonothermogenetics for noninvasive, deep-penetrating, and cell-type-specific neuromodulation by combining a thermosensitive ion channel TRPV1 with focused ultrasound (FUS)-induced brief, non-noxious thermal effect. Sonothermogenetics is a noninvasive and cell-typespecific neuromodulation approach with the capability to target the deep brain.
Predator and prey: The origin of antisubmarine warfare
Authors: Manstan Roy
Published: June 2021

The month America entered The War [That Did Not] End All Wars, in April 1917, Germany’s relentless U-boat predators hunted their prey throughout the Mediterranean and Atlantic, sending 400 ships to the bottom. During those 30 days, hundreds more were damaged and put out of commission. Soon after his arrival in England, Admiral Sims, Commander of U.S. Naval Forces in Europe, sent a warning to the Secretary of the Navy that with the “appalling destruction” by U-boats, the “unconditional surrender of the British Empire would inevitably take places….” After a three year stalemate along the Western Front, Germany was becoming dependent on the Unterseeboot, declaring: “[T]here is no possibility of bringing the war to a satisfactory end without ruthless U-boat warfare.” Briefly reaching back to 1776 when David Bushnell’s submersible vessel Turtle attempted to sink a British man-of-war, this presentation will focus on the emergence of submarine and antisubmarine technologies at the beginning of the 20th century. The U-boat solution would come from a cadre of scientists and engineers at the Naval Experimental Station in New London, CT, adapting the hydrophone to exploit a submarine’s vulnerability: they were extremely noisy. The predator now became the prey.
Expanding communication of acoustical knowledge around the globe: Examples of outreach and the use of social media
Authors: Morata Thais C.
Published: June 2021

For five decades, the National Institute for Occupational Safety and Health (NIOSH) has studied the effects of noise and disseminated public health information on hearing health. Today, the public expects greater transparency, responsiveness, and accountability, and organizations must respond with authenticity and engagement to maintain the public’s confidence. Social media channels have emerged as an effective platform for public health communication. While health communication specialists are integral to framing and delivering appropriate messages, scientists cannot remain disconnected from this process. Subject matter experts are uniquely positioned to leverage these tools to communicate their science directly to the public in a timely manner. This lecture will focus on NIOSH’s recent outreach and science communication efforts to reach the general public and include results of the Wiki4 Year Of Sound 2020 effort. This and several other examples are part of collaborative outreach activities with the CDC’s National Center for Environmental Health and other governmental agencies, several professional organizations (including the Acoustical Society of America), and the World Health Organization. [The findings and conclusions in this report are those of the author and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.]
Integrating ultrasound directed self-assembly and additive manufacturing to fabricate engineered materials
Authors: Raeymaekers Bart
Published: June 2021

Engineered materials comprising specifically designed patterns of particles embedded in a matrix material can display exotic physical properties when interacting with an external field, such as metamaterials (electromagnetic wave field) and structural materials (force field), to only name a few. Altering the pattern of particles that constitutes the microstructure of the engineered material enables tuning its properties. We describe a fabrication process to implement macroscale engineered materials layer-by-layer using additive manufacturing, where in each layer we organize a user-specified pattern of particles using ultrasound directed self-assembly to tailor the microstructure of the material. In contrast with previous demonstrations of fabricating engineered materials that are limited to laboratory-scale and/or 2D implementations, this process enables fabricating macroscale specimens with complex 3D geometry required for engineering applications. Hence, this platform technology has significant implications for fabricating engineered materials relevant to a wide range of applications including manufacturing of composite materials, engineered materials for acoustic and electromagnetic cloaking and sub-wavelength imaging, and 3D printing structures with embedded electrical wiring, among others.
The effect of moisture content on the acoustic characteristic of bioenergy feedstocks—Corn Stover
Authors: Doan Hung T. , Hakoda Christopher , Greenhall John , Pantea Cristian , Semelsberger Troy
Published: June 2021

Corn stover is increasingly being used as a bioenergy feedstock. From harvest to handling and storage, its inconsistent moisture content imposes limits on the industry's growth and profitability. We propose an acoustic approach that can detect changes in corn stover moisture content and shows the capability to propagate through corn stover and improve the moisture sensing range and accuracy as compared to currently available technologies. Using air-coupled transducers that operate at 20 kHz and a simple experimental setup, we determine the sound speed in corn stover. Signal analysis using cross-correlation and fast Fourier transform allows the calculation of sound speed and signal amplitude from the A-scan. An inverse relationship between the sound speed and the packing density of corn stover is found. Sound speed and transmission amplitude data enable the determination of corn stover’s moisture content between 10i% and 55%. The benefit of this technology also lies in its ability to sense through the center of a packed sample of corn stover at a density above 300 kg/m3. The improvement promises a decrease in the cost of handling and processing, which will help establish corn stover as an economically-viable bioenergy feedstock.
Some perspectives on the modeling of acoustic metasurfaces
Authors: Jing Yun
Published: June 2021

Numerical modeling is an important tool for the study of acoustic metasurfaces as it can shed light on the physical principles of these engineered acoustic structures and be used for optimization purposes. In this talk, I will discuss challenges that we have encountered in modeling acoustic metasurfaces using commerical software and semi-analytical models. I will focus on sound-absorbing acoustic metasurfaces and diffractive acoustic metasurfaces. I will also discuss the possibility of using open-source wave solvers (such as k-Wave and mSOUND) to model acoustic metasurfaces, which has been largely unexplored.
Spectral extended finite element method for band structure calculations in phononic crystals
Authors: Chin Eric B. , Mokhtari Amir A. , Srivastava Ankit , Sukumar N.
Published: June 2021

This talk introduces the extended finite element method (X-FEM) on structured higher-order (spectral) finite element meshes for computing the band structure of one- and two-dimensional phononic composites. The X-FEM enables the modeling of holes and inclusions in geometry through the framework of partition-of-unity enrichment. This reduces the burden on mesh generation, since meshes do not need to conform to geometric features in the periodic domain. Further, with iterative design processes such as phononic shape optimization, the need for remeshing is eliminated. To obtain theoretical rates of convergence with higher-order extended finite elements, careful consideration of curved geometry representation and numerical integration is required. In two dimensions, we adopt rational Bezier representation of conic sections or optimized cubic Hermite functions to model implicit boundaries described by level sets. Efficient computation of weak form integrals is realized through the homogeneous numerical integration scheme—a method that uses Euler’s homogeneous function theorem and Stokes’s theorem to reduce integration to the boundary of the domain. Ghost penalty stabilization is used to improve matrix conditioning on finite elements that are cut by a hole. Band structure calculations on perforated materials as well as on two-phase phononic crystals are presented that affirm the sound accuracy and optimal convergence of the method on structured, higher-order spectral finite element meshes.
A linguist's perspective on teaching communication disorders
Authors: Hagiwara Robert
Published: June 2021

I am a linguist in a linguistics department rather than a clinician in an accredited program, and thus some aspects of a typical intro speech and hearing science course are well beyond my capabilities and experience, e.g., clinical decision making, intervention, etc. My approach to teaching communication disorders to linguistics students has always been to focus on discussing the communication breakdown in relation to standard linguistic insights of a typical speaker/hearer, things like natural classes and markedness, content versus grammatical function, and so on. I ask my students to understand, for instance, what is going on when a child learns phonology or an adult brain processes language; what seems to be ‘breaking’ when a child presents a speech sound disorder or an adult presents aphasia; and how a “standard” linguistic view handle (or not) the relationship of these cases. While there are many outstanding textbooks intended to introduce the field of communication disorders to students entering the field, there are few suitable for a course from “my perspective“ aimed to linguistics students. Some years ago, I realized that I was probably going to have to write (or edit) one myself. In this presentation, I present my plans for the content and organization for this textbook.
Teaching phonetics in a flipped classroom
Authors: Baese-Berk Melissa M.
Published: June 2021

Within the typical undergraduate linguistics curriculum, phonetics can maintain a special status. Instead of a lecture with discussion sections, students are often faced with labs and assignments that look suspiciously like those in their science classes instead of their humanities and humanistic social science courses. As such, some students struggle in these classes when they are taught in traditional lecture-lab formats. Here, I present the format I have recently used for teaching phonetics—“flipping” the classroom. Rather than completing assignments outside of class as in a traditional lecture-style class, participants watch lecture modules outside of class and class time is devoted to demonstrations, tutorials, and working through labs and related content. This format has resulted in increased student satisfaction and increased performance on an array of assessments. I will specifically discuss how I design the lecture modules, how we incorporate the in-class activities, and how this can be modified for a remote classroom if COVID-19 restrictions persist.
Incorporating dialectal variation into the introductory phonetics course: The class is the data
Authors: Reed Paul E.
Published: June 2021

Recognizing and understanding social and regional variation is crucial for beginning speech science students as well as future speech-language clinicians. However, social variation of language is often confined to a single module or chapter that presents dialectal differences as divergent from some mainstream norm, rather than an essential element present in the speech of all persons. In this talk, I will discuss a series of in-class and homework activities that demonstrate and incorporate vocalic variation across several activities during an introductory phonetics semester. Discussion will focus on how to guide students toward recording and transcribing their own speech, building informative individual vowel plots, discussing and analyzing vowel plots in small groups, and also creating a class-wide vowel plot.
Fast and accurate demodulation of wideband signals
Authors: Gabrielaitis Mantas
Published: June 2021

We introduce a new convex-programming-based approach to amplitude demodulation of arbitrary-bandwidth signals. While featuring recovery guarantees for a wide class of relevant signals, the new method surpasses competing techniques in terms of computational efficiency by many orders of magnitude; this opens the door for previously inaccessible applications ofamplitude demodulation of arbitrary-bandwidth signals in online and large-scale offline settings. See https://arxiv.org/abs/2102.04832 for more information.
Extrapolation of Green's functions using the waveguide invariant
Authors: Song Hee-Chun , Byun Gihoon
Published: June 2021

A Green's function observed at one location can be extrapolated into adjacent ranges in shallow water by exploiting the waveguide invariant theory.
Plate-type acoustic metamaterials with strip masses
Authors: Langfeldt Felix , Gleine Wolfgang
Published: June 2021

Plate-type acoustic metamaterials (PAM) consist of a thin plate with periodically added masses. Similar to membrane-type acoustic metamaterials, PAM exhibit anti-resonances at low frequencies at which the transmission loss can be much higher than the mass-law without requiring a pretension. Most PAM designs previously investigated in literature require the addition of up to thousands of masses per square meter. This makes manufacturing of such PAM prohibitively expensive for most applications. In this contribution, a much simpler PAM design with strip masses is investigated. An analytical model is derived which can be used to estimate the modal properties, effective mass, and oblique incidence sound transmission loss of PAM with strip masses. For high strip masses (compared to the baseplate), this analytical model can be simplified to yield explicit expressions to directly calculate the resonance and anti-resonance frequencies of such PAM. The analytical model is verified using numerical simulations and laboratory measurement results are presented to demonstrate the performance of PAM with strip masses under diffuse field excitation and finite sample size conditions.
Estimation of bottom parameters in the New England Mud Patch using geophone and hydrophone measurements
Authors: Miller James H. , Potty Gopu R. , Lin Ying T. , Bonnel Julien
Published: June 2021

Measurements of acoustic pressure and particle velocity were made during the Seabed Characterization Experiment (SCEx) in the New England Mud Patch south of Cape Cod in about 70 m of water. The University of Rhode Island and Woods Hole Oceanographic Institution deployed the “geosled” with a four-element geophone array, a tetrahedral array of four hydrophones, and Several Hydrophone Receive Units (SHRUs) as data acquisition packages. In addition, a recently developed low frequency source, the interface Wave Sediment Profiler (iWaSP), was deployed to excite interface waves (Scholte waves) on the seabed. The geophone array was localized using the known locations of the small explosive sources and noise from the research vessel. Modal arrivals from broadband sources on geophones and hydrophones were used to invert for compressional and shear wave speeds and attenuation in the mud layer and the underlying sand layer. The Scholte wave arrivals from the iWaSP source measured by the geophone array also provided estimates for these parameters. The inversion results are compared to modeling using the viscous grain shearing (VGS) theory. [Work supported by the Office of Naval Research, Code 322 OA.]