bluuebunny/crossref_metadata_2025 huggingface dataset:
Governing with God: Religion, Resistance, and the State in Nigeria's Counter‐Trafficking Programs
Authors: Vanderhurst Stacey
Published: November 2017

Over the past fifteen years, the Nigerian government has stopped many young migrant women from trying to leave the country, identifying them as victims of human trafficking and referring them to a federal antitrafficking agency for protection and rehabilitation. Relatively few women accept these interventions outright, due in part to ingrained suspicion of state officials and institutions. This article uses ethnographic research from one state‐run shelter where these would‐be migrant women were detained to examine how state counselors there justified their actions and how migrant women interpreted them. Where the moral authority of the state has been depleted, it shows how shelter staff urged residents to find trust in government through trust in God, and how women in turn made claims on the state through religious idioms of conversion and salvation. Ultimately, it demonstrates how ad hoc relationships of governance are forged in one fervently contested encounter between citizens and the state in Nigeria.
“Bushmen” in the Law: Evidence and Identity in Botswana's High Court
Authors: Sapignoli Maria
Published: November 2017

This article, based on ethnography and analysis of court transcripts, considers the case that a group of San and Bakgalagadi brought against the government of Botswana to the country's High Court. The proceedings and judgment in the case illustrate the ways that court process gives life to legal categories. This is particularly clear in the evidence filed in defense of indigenous rights because the knowledge and experience of collective claimants is often at odds with the premises and power structures of state courts. Evidence and expertise are brought to bear as ways to lend authority to the facts that make up an argument. Several key concepts were discussed in court, notably those of “applicants,” “Bushmen,” and “native title,” each of which had important consequences for the claimants. Following the lives of the legal categories from observations within the courtroom itself, to their lasting influence on the applicants to this day, this article illustrates the durability and political significance of the concepts and categories elaborated in the verdict.
Rethinking American Indian and Non‐Indian Relations in the United States and Exploring Tribal Sovereignty: Perspectives from Indian Country and from Inside the Bureau of Indian Affairs
Authors: Lambert Valerie
Published: November 2017

This article uses materials from field research conducted at the level of tribal homelands and at the federal level of the Bureau of Indian Affairs to rethink and reconceptualize Indian–non‐Indian relations and federal–Indian relations in the United States. I document the ways Chickasaw and Choctaw tribal officials are moving beyond the “deadliest enemies” model of Indian–non‐Indian relations in tribal homelands in their pursuit of strategies that expand the role of tribal governments, mobilize support from local non‐Indians for American Indian tribal empowerment and resurgence, and institutionalize a reordered regional political hierarchy. Cultural constructions of tribal sovereignty undergird these strategies and the transformations that are unfolding in the territories of the American Indian tribe in which I am enrolled and its neighbor tribe. Turning to a second site of participant‐observation field research, I document the ways a different but related construction of tribal sovereignty drives the work of the Bureau of Indian Affairs, an agency whose workforce is more than 95 percent American Indian. Federal–Indian relations are shown to take shape through systematic responses to bureaucratic imperatives, the circulation of legal and popular constructions of Indian identity, and the resistance to segregation of the categories of “federal” and “Indian” in federal–Indian affairs.
The Impact of Demographic Representation on Absences and Suspensions
Authors: Holt Stephen B. , Gershenson Seth
Published: November 2017

Representative bureaucracy theory is central to public administration scholarship due to the likely relationship between the demographic composition of the public workforce and both the actual and perceived performance of public organizations. Primary school classrooms provide an ideal context in which to test the predictions of representative bureaucracy theory at the micro (student) level. Specifically, as parents have at least some agency over primary school students’ daily attendance, absences partially reflect parental assessments of their child's school, classroom, and teacher. Ensuring students attend school each day represents an effort at coproduction on the part of parents. The representativeness of the teacher workforce, and specifically that of the student's classroom teacher, is therefore likely to influence student absenteeism. Similarly, student suspensions reflect students’ relationships with their teacher, students’ comfort level in the classroom, and teachers’ discretion in the referral of misbehavior. These academically and socially important outcomes provide convenient, objective measures of behaviors that are likely influenced by street‐level representation. Using longitudinal student‐level administrative data from North Carolina, we use a two‐way (student and classroom) fixed effects strategy to identify the impact of student–teacher demographic mismatch on primary school students’ absences and suspensions. We find that representation among street‐level bureaucrats significantly decreases both absenteeism and suspensions and that these effects can be given a causal interpretation. This pushes literature forward by establishing the importance of demographic representation in shaping productive relationships between individual bureaucrats and clients.
Network Structure and Governance Performance: What Makes a Difference?
Authors: Yi Hongtao
Published: November 2017

Comparing and evaluating the performance of governance networks are important tasks for researchers and practitioners of network governance and public administration. Limited by the lack of network data across space and time, the study of network performance and effectiveness at the network level is not on pace with advances in theories and methodologies in network analysis. With a novel methodology to measure clean energy governance networks using hyperlink network analysis across the contiguous United States, this article collects a large sample of self‐organizing policy networks in the same policy domain across geographic locations. This article proposes that governance networks with high overall bridging and bonding social capital perform better. Regression analyses show that network structures have statistically significant effects on governance outcomes. States with high average closeness and average clustering in their governance networks are more likely to have faster clean energy development.
Peripheral airway dysfunction and relationship with symptoms in smokers with preserved spirometry
Authors: Jetmalani Kanika , Thamrin Cindy , Farah Claude S. , Bertolin Amy , Chapman David G. , Berend Norbert , Salome Cheryl M. , King Gregory G.
Published: November 2017

Background and objective

Smokers develop respiratory symptoms and peripheral airway dysfunction even when spirometry is preserved. Multiple breath nitrogen washout (MBNW) and impulse oscillometry system (IOS) are potentially useful measures of peripheral airway function but they have not been compared in such subjects. We hypothesized that MBNW and IOS are jointly abnormal in smokers with normal spirometry and that these abnormalities relate to respiratory symptoms.

Methods

Eighty smokers with normal spirometry completed a symptom questionnaire, had ventilation heterogeneity in diffusion (Sacin) and convection‐dependent (Scond) airways and trapped gas volume at functional residual capacity as a percentage of vital capacity (%VtrFRC/VC) measured by MBNW. Respiratory resistance and reactance at 5 and 20 Hz were measured using IOS.

Results

Respiratory symptoms were reported in 55 (68%) subjects. Forty (50%) subjects had at least one abnormal MBNW parameter, predominantly in Sacin. Forty‐one (51%) subjects had at least one abnormal IOS parameter, predominantly in resistance. Sixty‐one (76%) subjects had an abnormality in either MBNW or IOS. Chronic bronchitis symptoms were associated with an increased Scond, while wheeze was associated with lower spirometry and an increased resistance. Abnormalities in MBNW and IOS parameters were unrelated to each other.

Conclusions

Respiratory symptoms and peripheral airway dysfunction are common in smokers with normal spirometry. Symptoms of chronic bronchitis related to conductive airway abnormalities, while wheeze was related to spirometry and IOS. The clinical significance of abnormalities in peripheral airway function in smokers remains undetermined.
The vicious layering of multilevel governance in Southern Europe: The case of elderly care in Italy and Spain
Authors: Arlotti Marco , Aguilar‐Hendrickson Manuel
Published: November 2017

Aging and changes in family arrangements and female employment have brought about important policy developments in long‐term care (LTC). Southern European countries have relied for a long time on family care and residual social care for the dependent elderly. Two paradigmatic cases, Italy and Spain, have shown two apparently different trends during the last 15 years: while in Italy, reforms seem to have been persistently blocked, in Spain, an ambitious reform has fallen short of expectations.

Based on data on services and institutional arrangements, the article shows that a complex and inconsistent allocation of responsibilities across government levels, a sort of “vicious layering” of multilevel governance, may be playing a key role in this situation. The article discusses the dysfunctional effects of such arrangements, namely territorial inequalities, cost‐shifting between government levels and towards users, and misallocation of resources.

We suggest that the development and reform of LTC in Southern European countries must address these problems if they want to avoid getting marooned by a complex network of vetoes and resource allocation problems.
Mindreading and Psycholinguistic Approaches to Perspective Taking: Establishing Common Ground
Authors: Apperly Ian
Published: November 2017

In this commentary on “Memory and Common Ground Processes in Language Use,” I draw attention to relevant work on mindreading. The concerns of research on common ground and mindreading have significant overlap, but these literatures have worked in relative isolation of each other. I attempt an assimilation, pointing out shared and distinctive concerns and mutually informative results.
Oxytocin mediates the beneficial effects of the exercise training on breast cancer
Authors: Alizadeh Ali Mohammad , Heydari Zahra , Rahimi Mostafa , Bazgir Behzad , Shirvani Hossein , Alipour Sadaf , Heidarian Yassaman , Khalighfard Solmaz , Isanejad Amin
Published: November 2017

New Findings

What is the central question of this study?

We hypothesized that potential anti‐tumour effects of exercise training might be mediated by oxytocin and explored the underlying mechanisms in a mouse model of breast cancer.

What is the main finding and its importance?

Interval exercise training, by inducing oxytocin secretion, may reduce the activity of the PI3K/Akt and ERK pathways, and consequently, results in a smaller tumour volume in a mouse model of breast cancer.

Exercise training can affect the growth of breast tumours. We hypothesized that exercise training might reduce breast tumour growth by inducing oxytocin (OT) secretion and its related signalling pathways, such as PI3K/Akt and ERK. Therefore, 56 BALB/c mice were equally divided into seven groups to study the effects of OT and atosiban (an oxytocin receptor antagonist) together with interval exercise training on mammary tumour growth, as well as tumour‐related signalling pathways, including PI3K/Akt and ERK. Animal weight, OT plasma concentration, tumour weight and volume were measured at the end of the study. PI3K/Akt and ERK were evaluated by Western blot and qPCR assays. The results showed that OT plasma concentration was significantly increased in trained animals. The volume and weight of tumours were decreased significantly after both exercise training and OT administration. The expression of genes involved in tumour cell proliferation, such as PI3KR2, Akt and mTOR, was notably lower in the exercise‐trained and OT‐treated groups. Furthermore, the expression of genes involved in cell apoptosis, such as caspase‐3 and Bax, was significantly increased in the tumour tissues. In addition, Western blot results showed that phosphorylated Akt and ERK were significantly decreased in the exercise training and OT groups compared with the tumour group. Interestingly, atosiban reversed these effects. These results indicated that interval exercise training, acting via OT secretion, may reduce PI3K/Akt and ERK axis activities, and consequently, decrease tumour volume and weight in a mouse model of breast cancer.
Improved Quantification of Exergy Destruction in Mechanical Cooling Tower Considering All Tower Inlet Parameters
Authors: Singh Kuljeet , Das Ranjan
Published: November 2017

The present work establishes an improved experimentally validated analysis to predict performance and exergy-related parameters of a mechanical draft cooling tower involving wooden splash fills. Unlike earlier studies, which accounted for the effect of at most three tower inlet parameters for the exergy analysis, the present study simultaneously considers all five inlet parameters affecting the tower exergy performance. To simultaneously predict outlet air and water conditions, an optimization algorithm involving discrete functions of dry- and wet-bulb temperatures is used in conjunction with the mathematical model derived from mass and energy conservations within the control volume involving Bosnjakovic correlation. From practical point of view, five inlet parameters such as dry-bulb temperature, relative humidity, water temperature, water, and air flow rates are selected for the exergy analysis. Thereafter, the influence of all inlet parameters on the tower performance is analyzed on various important exergy-related factors. The quantitative analysis reveals that the inlet air humidity, water inlet temperature, and the inlet water mass flow rate significantly influence the air and water exergy changes. The present study also reveals that among the five inlet parameters, the water temperature, air humidity, and air mass flow rate are primarily responsible for the exergy destruction. Furthermore, it is observed that the second law efficiency is mainly governed by the inlet air flow rate. The present study is proposed to be useful for selecting the tower inlet parameters to improve exergy performance of mechanical cooling towers.
Failure Analysis of Glass-Reinforced Epoxy Pipes Under Internal Hydrostatic Pressure: A Comparison With the Split Disk Test Method
Authors: Mahdavi H. R. , Rahimi G. H. , Farrokhabadi A.
Published: November 2017

In this paper, the ultimate hoop strength of an industrial (±55 deg)9 filament-wound glass-reinforced epoxy (GRE) pipe as a short-term test is determined according to the ASTM D-1599 standard by performing the internal hydrostatic pressure test. After the test, the failure surface of the pipe is photographed by a high magnification camera, and in addition, the explanations are presented about the type of failure. The main purpose of this study is to compare the results obtained for the ultimate hoop strength and failure mechanisms of the pipe by using the internal hydrostatic pressure test with that by the split disk test method according to the ASTM D-2290 standard in the previous work.
Design and characterization of a microreactor for spatially confined atomic layer deposition and in situ UHV surface analysis
Authors: Chen Jiun-Ruey , Zhang Wenyu , Nahm Rambert K. , DiFeo Michael A. , Engstrom James R.
Published: November 2017

The authors report the design and characterization of a microreactor probe that enables gas-phase reactions such as atomic layer deposition (ALD) at low-to-medium vacuum, which is coupled directly to an ultrahigh vacuum (UHV) analysis chamber for subsequent in situ surface characterization without an air break. Avoiding this air break is critical to developing a complete understanding of the growth of ultrathin films, particularly in the early stages of growth. Making use of a precisely defined gap between the microreactor probe and the substrate surface, the reactants are well confined in the reaction zone (total volume ∼1 cm3) by the use of “curtain gas” flow. Computational fluid dynamics was used to simulate both the steady-state and transient operations of the microreactor and the surrounding UHV chamber in which fluid flow, heat transport, and mass transport were considered. The authors provide two examples of the efficacy of the design by considering exposure of a Cu substrate to I2(g) vapor, and conducting the ALD of ZrO2 using Zr[N(C2H5)(CH3)]4 and H2O as reactants, the latter at a total pressure of 18 Torr. In both cases, the authors achieved excellent confinement of the reactants to the central reaction zone, as confirmed by in situ spatially resolved x-ray photoelectron spectroscopy.
The spatial coherence of noise fields evoked by continuous source distributions
Authors: Buerger M. , Abhayapala T. D. , Hofmann C. , Chen H. , Kellermann W.
Published: November 2017

In this work, analytic expressions for the spatial coherence of noise fields are derived in the modal domain with the aim of providing a sparse representation. For this purpose, the sound field in a region of interest is expressed in terms of a given pressure distribution on a virtual surrounding cylindrical or spherical surface. According to the Huygens–Fresnel principle, the sound pressure on this surface is represented by a continuous distribution of elementary line or point sources, where orthogonal basis functions characterize the spatial properties. To describe spatially windowed pressure distributions with arbitrary angular extensions, orthogonal basis functions of limited angular support are proposed. As special cases, circular and spherical pressure distributions with uncorrelated source modes of equal power are investigated. It is shown that these distributions result, respectively, in cylindrically isotropic and spherically isotropic, i.e., diffuse noise fields. The analytic expressions derived in this work allow for a prediction of the spatial coherence between arbitrary positions within the region of interest, such that no microphones need to be placed at the actual points of interest. Simulation results are presented to validate the derived relations.
Disability rights aspects of ambient noise under the Americans with Disabilities Act for people with auditory disorders
Authors: Fink Daniel
Published: November 2017

The goals of the disability rights movement are full enjoyment, active inclusion, and equal participation in society for people with disabilities. The Americans with Disabilities Act (ADA) guarantees full and equal enjoyment of places of public accommodation for them. People with partial hearing loss, tinnitus, and hyperacusis meet the ADA definition of having a disability but currently have no legal protection under ADA. People with 25–40 decibel hearing loss cannot understand speech in noisy places, with or without hearing aids. They require ambient noise levels below 60 A-weighted decibels with reverberation times under 0.50 seconds to understand speech. Noise worses symptoms for those with tinnitus and hyperacusis. Noisy restaurants and other indoor places deny full enjoyment and equal participation in public life to people with these auditory disorders. Legislative and regulatory actions are needed to provide quiet environments, with established noise standards vigorously enforced. Technologies and environmental modifications to control noise and reverberation are well known, readily available, and relative inexpensive. The simplest modification is merely turning down the volume of amplified sound. Universal design for quiet facilitates communication for everyone and prevents hearing loss, tinnitus, and hyperacusis in those without auditory disorders.
Champagne bubble acoustics
Authors: Spratt Kyle S. , Lee Kevin M. , Wilson Preston S.
Published: November 2017

Sparkling wine, such as the variety coming from the Champagne region of France, is a beverage that is at least partially famous for its carbon dioxide bubbles, a byproduct of the secondary fermentation process that occurs after bottling. A well-known theory, though hardly accepted universally, posits that the quality of a sparkling wine can be ascertained from the characteristics of its bubbles, such as bubble size distribution and rate of production. This talk describes a preliminary investigation to monitor the characteristics of sparkling wine bubbles using passive acoustic measurements, wherein bubble parameters are estimated from the power spectral density of the ambient bubble noise. Measurements made on a variety of sparkling wines will be presented.
Describing sonic environment of Chinese restaurants using a mathematical model
Authors: Chung Andy , To W. M.
Published: November 2017

A restaurant is commonly chosen as a venue for gathering because it serves both the dining and meeting purposes in one go, and is good for people who are busy and keen on balancing social, work, and family lives with limited time. Depending on the anticipating nature of meeting, people tend to choose a restaurant with the right mood for communication as well as the general perception of the sonic environment in whether it favors quiet conversations or louder chats. This paper presents the results of a survey on the sonic environment of a number of Chinese restaurants in Hong Kong and a mathematical model for the associated description.
Efficient prediction of the transmission loss of curved systems with attached noise control treatment
Authors: Kesour Kamal , Atalla Noureddine
Published: November 2017

This paper discusses the modeling of the transmission loss of curved panels with attached sound absorbing materials (foam or fiber). Two approaches are compared. The first is a classical coupled FEM/BEM (Finite element/Boundary element) approach wherein the panel and its cavity are modeled using the FEM and the blocked pressure on the excitation side and radiation from the transmission hole are modeled using the BEM. The second is an approximate approach using a Patch Transfer Function (PTF) method to describe the coupling between the panel, the sound package, the cavity and the transmission hole. To compute the PTF relations, the panel and the cavity are described by FEM while the effect of the sound package is described by a Green’s function methodology using the Transfer Matrix Method (TMM) to speed up the process. It is shown that this latter approach is quick and accurate enough to estimate the TL of the system. Moreover, it allows for a quick comparison of the performance of various sound packages for a given curved panel. Several examples are presented to demonstrate the validity of this approximation and demonstrate its range of applicability and usefulness.
Chester McKinney: A legacy of high frequency sonar development at Applied Research Laboratories, The University of Texas at Austin
Authors: Huckabay John
Published: November 2017

Following the Korean War, improvements in high frequency, high resolution sonar were needed in order to successfully prosecute naval mines. Chester McKinney led an effort at Applied Research Laboratories (formerly Defense Research Laboratories), The University of Texas at Austin (ARL:UT), to make progress in this important area of research; and began a lifelong passion for Chester to pursue both basic and applied research in high frequency acoustics as applied to mine countermeasures. This research has been performed over many years by numerous scientists and engineers at ARL:UT and continues today. Based on this research, both experimental and operational high frequency, high resolution sonars were constructed, tested, and employed. This paper will explore some of these important sonar developments as well as some of the underlying physics. These developments span from analog implementations of CTFM sonars, pulse sonars, beamformers, and signal processing to early implementations of digital sonars and digital signal processing. Key parts of sonar research will be traced from the AN/UQS-1 to the AN/SQQ-14, AN/SQQ-16, AN/WQS-1, and the Data Collection Test Bed Sonar (development model for the AN/SQQ-32).
Implications of the evolving sound speed field on detection and classification of targets in shallow water
Authors: Dall'Osto David R. , Blumberg Alan , Stein Peter J. , Thorsos Eric I. , Gruhl Amy
Published: November 2017

Acoustic refraction caused by gradients in the sound speed field within a region covered by an active sonar system affects its performance and quality of information. From the perspective of target strength, refraction can focus sound and enhance target returns, or it can redirect sound and create shadow zones where targets will drop out. These effects depend on the evolving sound speed field, as well as the placement of the transmitters and receivers. In addition, focused sound at the water-sediment interface can produce a small region of enhanced backscatter, which can rise above the nominal reverb level by 6 dB or more. Continuous evolution of the time-dependent sound speed field can cause these relatively compact returns to appear as moving targets, increasing false-alarm detections. Advances in fine scale oceanographic models facilitate studying these propagation effects, both the enhanced/degraded target returns and the target-like bottom backscattered features. A combined acoustic and oceanographic model is presented for discussion on what conditions cause these effects, the possibility of identifying their occurrence within data, and what the consequences are on a practical sonar system operating in shallow water.
Comparing lexical decision reaction times and error rates for Southern and British English
Authors: Llorens Mairym
Published: November 2017

The English spoken in the southern states of the US as well as the “received pronunciation” of British English are two varieties that the majority of students at the University of Southern California are relatively unfamiliar with. Some of the popular stereotypes surrounding the two groups of speakers, however, diverge: while it has been shown that certain listeners consistently down-grade Southern speakers on positive attributes like intelligence and competence, no such effect is observed for British speakers. This study aimed to investigate the impact of negative stereotypes on lexical decision reaction times and error rates. A list containing high frequency words, low frequency words and non-words was constructed and a trained voice actor recorded the stimuli in both British and Southern English. Participants heard half of stimuli in each variety. Participants tended to incorrectly reject more real words in Southern English than British. These errors occurred in trials with relatively short reaction times. British English stimuli tended to have slower reaction times. The implications of these findings in light of other experiments comparing lexical decision in these and other varieties of English are discussed.
Dynamic trajectories of tense vs. lax vowels in the American South
Authors: Renwick Margaret E.
Published: November 2017

Regional variation in American English speech is often described in terms of vowel shifts, in which one or more sounds “move” within the X,Y plane of height and backness captured by vowels’ first and second formant values. Such shifts indicate which sounds are converging or diverging, providing predictions for language change and variation. Static characterizations of shifting, with a single pair of F1/F2 values taken near the vowels’ midpoint or intensity peak, provide an approximation of vowels’ relations, but fail to capture acoustic information during the rest of the vowels’ time course. In Southern dialects, where front tense and lax vowels may “swap places,” static measures show strong overlap between these pairs and thus predict mergers between, e.g., beet-bit, bait-bet; instead, these mergers’ clear lack of occurrence indicates the inadequacy of static methods. Using data from 64 semi-spontaneous linguistic interviews in the Digital Archive of Southern Speech, we model the shape and movement of vowels’ dynamic trajectories. Formant values taken at five locations show that tense and lax vowels have distinct beginning and endpoints, though they pass through shared acoustic space near their temporal midpoints. Sociolinguistic factors affecting trajectories’ length and shape are investigated using Generalized Additive Mixed Models.
Social and linguistic influences on the phonetic imitation of Southern American English vowels
Authors: Dossey Ellen
Published: November 2017

This study investigated the effect of regional biases on phonetic imitation, specifically exploring imitation of Southern American English by Midwesterners in a lexical shadowing task. To manipulate the regional biases at play, participants received different information about the model talker’s regional origins. They were either told she was from the Midwestern city of Columbus, Ohio; the Southern locations of Eastern Kentucky or Savannah, Georgia; or nothing at all. After shadowing, participants completed a survey about their perceptions of the talker and her supposed region of origin. Vowel formant frequencies and trajectories were analyzed for imitation. Significant imitation was observed, although not all vowels were imitated equally. The survey revealed that the Southern locations differed in the biases associated with them, and that the Midwest was more socially desirable than the South. However, the survey responses were not predictive of imitative behavior. The vowel selectivity in imitation may be due to linguistic factors, such as the baseline distance between the model talker’s and participants’ vowels, or social factors such as the relative level of social stigma associated with the vowel variants. The results of this study suggest that imitation may be partly automatic but also influenced by certain language-external social information.
Vowel acoustic characteristics of Southern White English produced by speakers from New Orleans area, Louisiana
Authors: Chung Hyunju , de Mahy Lauren A.
Published: November 2017

This study aims to characterize vowels produced by speakers from the New Orleans area, Louisiana. The state of Louisiana is well known for its various dialects spoken across the regions. Despite the possible methodological issues and challenges researchers face for studying speech and language of young children (e.g., Oetting, & McDonald, 2002), vowel characteristics of different dialects, especially those of the New Orleans area, have not been well investigated. In the current study, vowels produced by speakers of Southern White English of New Orleans will be compared to those of two other regions of Louisiana. Participants included a total of 30 female adults, ranging in age from 18 to 25. There were 10 participants in each of the New Orleans, other Southern, and Northern Louisiana area. Each participant was asked to produce English words containing 11 different monophthongs three times in a randomized order. Vowel duration, the first three formant frequencies at the vowel midpoint, and formant trajectories were measured and analyzed. Acoustic differences in vowels are expected among speakers of three different regions. The outcome of the current study will provide normative data necessary for evaluating children’s vowel articulation skill of diverse dialectal backgrounds.
Non-reciprocal acoustic metamaterials for full-duplex communications and imaging
Authors: Alu Andrea , Wiederhold Curtis , Quan Li , Sounas Dimitrios
Published: November 2017

In this talk, we discuss our recent efforts in the area of non-reciprocal metamaterials based on moving media or spatiotemporally modulated acoustic elements, aimed at realizing efficient and compact isolation and circulation in acoustic devices. We discuss the relevance of these concepts for new-generation acoustic devices that realize isolation in guided and radiating structures, with relevance for acoustic imaging applications, including ultrasound and sonar technology, and for sound communications. Non-reciprocal responses and built-in isolation and circulation in waveguides and in radiating elements offers the opportunity of translating the advantages recently enabled by non-reciprocal components in electromagnetics, based on full-duplex signal transmission, to acoustic technology.
High speed acoustic communication with orbital angular momentum multiplexing
Authors: Shi Chengzhi , Dubois Marc , Wang Yuan , Zhang Xiang
Published: November 2017

Acoustic communication is critical for underwater application such as deep ocean scientific explorations, off-shore industrial controls, and ocean environment monitoring. This is because other techniques using electromagnetic waves such as RF communications are difficult for underwater applications due to the strong absorption of water in such a frequency. Optical communication, on another hand, suffers from the light scattering from micro-particles or marine life making long range underwater optical communication very challenging. Therefore, using acoustic waves to transmit information is currently the dominate technique for underwater applications including data collection and remote control of off-shore benthic stations. However, the low frequency bandwidth available for acoustic communication limits the data transmission rate and information capacity or content. We propose and experimentally demonstrate here a new approach using the orbital angular momentum (OAM) of acoustic vortex beams which provides a new and independent channel that enhances the data transmission rate by eight fold. The OAM multiplexing method demonstrated here will impact significantly on future underwater communications.
Constant amplitude sound waves in non-Hermitian metamaterials
Authors: Rivet Etienne , Brandstötter Andre , Makris Konstantinos , Rotter Stefan , Lissek Herve , Fleury Romain
Published: November 2017

We investigate the possibility for acoustic waves to propagate with a constant amplitude in disordered media. We find that this remarkable property is possible if one adds a tailored distribution of gain and loss on top of the disorder, making the medium non-Hermitian. We present the theory of constant-amplitude acoustic waves in both cases of continuous and discrete media, and provide an experimental demonstration in a metamaterial at audible frequencies.
Passive, broadband suppression of radiation of low-frequency sound
Authors: Godin Oleg A.
Published: November 2017

Plane gas-liquid interface becomes anomalously transparent for low-frequency sound, and essentially all energy radiated by a compact sound source in fluid is channeled into the gas when the source is within a fraction of wavelength from the interface [O.A. Godin, Phys. Rev. Lett. 97, 164301 (2006)]. This is in contrast to high-frequency behavior, where the interface approximates a pressure-release boundary, and only a very small fraction of energy escapes the liquid. This paper investigates whether a similar effect of suppression of unwanted low-frequency sound radiation by underwater sources can be achieved in a wide frequency band by using compact, acoustically soft objects. Low-frequency asymptotics of acoustic Green’s functions in the presence of spherical and cylindrical scatterers are used to quantify radiation suppression by simple shapes. Dependence of the radiation suppression efficiency in a homogeneous fluid and in underwater waveguides on mechanical properties of the soft objects is discussed. Feasibility of passive suppression of underwater sound radiation with and without employing acoustic metamaterials is addressed. [Work supported by ONR.]
Sound radiation from a finite cylindrical shell with an irregular-shaped acoustic enclosure
Authors: Yang Desen , Zhang Rui , Shi Shengguo , He Tengjiao
Published: November 2017

In practical situations, large machinery equipments are usually located in underwater vessels and change the regular-shaped cavity into an irregular one. Due to the existence of the machinery equipments, the sound transmission and radiation are difficult to express analytically. This paper models and analyses the noise radiation of a cylindrical shell excited by an internal acoustic source. The cylindrical shell contains a machinery equipment modelled as a rectangular object attached to shell with a spring-mass system. The acoustic field of cavity is computed by an integro-modal approach. Effects of object size on the coupling between acoustic modes and structural modes are investigated. Meanwhile, the relationship between volume of the object and sound radiation is studied. Numerical results show that the existence of the object gives rise to a more effective coupling between the structure and the enclosure compared with a regular-shaped cavity.
Changing an existing performance space from a single purpose use to a multipurpose space or creating a multipurpose space from an existing performance space not acoustically suitable for any performances
Authors: Coffeen Robert C.
Published: November 2017

Occasionally, a performance space is created for a particular use such as drama and later it realized by the owner and the users that the space should be acoustically suitable for multipurpose use. Also performance spaces are encountered that do not suitably serve performances of any type from an acoustical viewpoint but that must properly serve performances of various types. Examples of both situations are discussed and acoustical data for both situations will be presented.
Case study: Eccles Center for the Performing Arts
Authors: Freiheit Ronald , Hildebrand Matthew S.
Published: November 2017

Cinemas and movie theatres have specific room acoustic requirements that are well understood in the industry. Recent technologies such as Dolby Atmos and DTS:X provide an exciting spatial audio experience using a high number of audio tracks dynamically rendered to loudspeakers located in both the overhead and lateral planes. But what happens when the same venue is utilized for both motion picture screenings and acoustic performances? In this paper, active acoustics processing is integrated into existing cinematic surround sound architecture to provide a unique solution that promises flexibility rather than compromise. Design objectives, limitations, and performance of the integrated systems are reviewed.
A trio of multi-purpose halls, 1995–2016: Aronoff, Overture, and Hancher
Authors: Myers Joseph W.
Published: November 2017

The Aronoff Center in Cincinnati OH (1995) includes a 2700-seat multi-purpose hall used as a roadhouse, with a particular focus on touring Broadway shows. The Overture Center in Madison, WI (2005), has a 2250-seat multi-purpose hall that is the home to a professional symphony orchestra and opera company, as well as hosting touring Broadway shows. Hancher Auditorium in Iowa City IA (2016) has an 1,800-seat multi-purpose hall that acts as a roadhouse for a broad variety of performance types, as a presenter for dance, and as the largest performance space for the University of Iowa's arts programs. All three performing arts centers had Pelli Clarke Pelli as design architect, Theatre Projects Consultants as theater consultant, and Kirkegaard Associates as acoustics consultant. This presentation examines what these halls have in common, how they are different, and what drove these differences. It looks specifically at the degree to which the differences are a design response to the particular program of each room and the degree to which they reflect changes over time in design approach or design requirements.
Biological effects and the Grain-Shearing model of wave propagation in unconsolidated sediments
Authors: Buckingham Michael J.
Published: November 2017

The Grain-Shearing (GS) model of wave propagation in unconsolidated sediments is embodied in two sets of dispersion relations, one for the compressional wave and the other for the shear wave. Besides frequency, these expressions for the wave speed and attenuation depend on the physical properties of the sediment, notably the bulk density and porosity. They also involve a material exponent, n, and grain shearing coefficients that are associated with the sliding of grains against one another, which is a non-linear, stick-slip type of process that is controlled by micro-asperities on the surface of the grains. Bioturbation is known to affect both the bulk density and porosity of sediments, while biogenic coatings of mineral grains modify the surface roughness, which alters the grain-shearing coefficients. The magnitude of the effects of bioturbation and biogenic coatings on the wave speeds and attenuations predicted by the GS theory will be discussed, based on available biological information in the literature. [Research supported by ONR.]
Effects of marine infauna on the acoustic properties of sediment
Authors: Ballentine Will M. , Dorgan Kelly M. , Lee Kevin M. , Ballard Megan S. , McNeese Andrew R. , Wilson Preston S. , Venegas Gabriel R.
Published: November 2017

Marine infauna alter the surrounding habitat in many ways. Compact mud burrows, tubes built from shell hash, and large subsurface galleries are a few examples of these alterations. Structural changes such as these can have varying effects on the geoacoustic properties of sediment. Here, we investigate how infauna may affect the sound speed and attenuation in sediments both in natural diverse communities of organisms, and in laboratory mesocosm experiments using controlled monocultures of species representing potentially important functional groups. Field studies were conducted at Petit Bois Pass off the coast of Dauphin Island, Alabama in May 2017 in which sediment cores were collected and brought back to the lab for acoustic measurements. These measurements can be directly compared with those taken in situ using a deployable field apparatus. For sediments with both natural and manipulated communities of infauna, sound speed and attenuation were measured at multiple depths and at high frequencies with wavelengths corresponding to the scales of expected impacts of individual organisms (100–400 kHz) to assess the effects of different infaunal functional groups.
Combined subharmonic and ultraharmonic intravascular ultrasound imaging
Authors: Shekhar Himanshu , Rowan Jeffrey S. , Doyley Marvin M.
Published: November 2017

Abnormal proliferation of the vasa vasorum has been implicated in the rupture of atherosclerotic plaques. Imaging the vasa vasorum could help clinicians identify rupture-prone plaques and guide the choice of therapy. We hypothesized that subharmonic and ultraharmonic modes can be combined to improve the performance of contrast-enhanced intravascular ultrasound (IVUS) imaging. To test this hypothesis, vessel phantoms perfused with phospholipid-shelled ultrasound contrast agent (Targestar-P®, Targeson, Inc., San Diego, CA) were visualized using either subharmonic, ultraharmonic, or combined subharmonic and ultraharmonic modes. Flow channels, as small as 0.8 mm and 0.5 mm in diameter, were imaged using commercial peripheral and coronary imaging catheters at 12 MHz and 30 MHz transmit frequencies, respectively. Subharmonic and ultraharmonic imaging modes attained contrast-to-tissue ratios (CTRs) of 18 ± 2 dB and 20 ± 2 dB at 12 MHz transmit frequency, and 9 ± 2 dB and 13 ± 1 dB at 30 MHz transmit frequency, respectively. Combining subharmonic and ultraharmonic modes enhanced the CTRs to 33 ± 3 dB and 25 ± 2 dB at 12 MHz and 30 MHz transmit frequencies, respectively. These preliminary findings support the continued investigation of combined subharmonic and ultraharmonic IVUS for vasa vasorum imaging.
Classroom demonstration of synthetic aperture and array concepts
Authors: Smith Chad M.
Published: November 2017

Although often time consuming to develop and present, classroom demonstrations are an effective tool used in physics education. This talk walks through a demonstration of the basic concepts of array processing and synthetic aperture sonar. An emphasis has been placed on limiting equipment and setup time required to implement this demonstration, while allowing the presenter break the discussion into several conceptual topic areas. Primary topics include pulse compression and temporal/range resolution, array aperture footprint and azimuthal/range resolution, influence of transmitter and receiver beampatterns, and the importance of temporal coherence and measurement platform motion. Hardware require for this demonstration can be made as simple as a speaker and a single electret microphone used with a common PC soundcard.
Infrasound blade pass frequency transmissibility measurements inside homes near wind turbines
Authors: Metelka Andy
Published: November 2017

Penetration of wind turbine blade pass frequencies are compared at different homes and various rooms show how levels change with wind direction and wind speed. Rooms facing turbines exhibited higher penetration compared to basement rooms, indicating air borne transfer paths vs. ground borne vibration. Construction characteristics of different homes are also compared using transmissibility calculations. Older homes exhibited higher transmissibility while newer airtight homes, under certain conditions, had lower transmissibility.
Politics, regulatory, and acoustic failures
Authors: Squire Natalie J.
Published: November 2017

There have been three senate inquiries in recent years, all of which have called for regulatory reform. Noise related nuisances and associated amenity detriments are very often attributed to the operation of nearby wind turbines. In many circumstances, disturbances are reported despite the reports of acoustic experts concluding that the wind farm is operating in compliance with the noise limits conditioned in relevant planning approvals. The current practise whereby wind farm operators directly engage acousticians requires review. This is particularly so in the state of Victoria where under-resourced municipal councils, usually without the technical capacity to understand complex acoustic issues, are now responsible for wind farm permit regulation and enforcement—and a state where the EPA plays no formal role in the assessment of noise or mitigation of complaints of noise pollution emitted from a wind farm. The societal benefits of independent acoustic reporting and the importance of peer review is discussed in relation to the Waubra and Cape Bridgewater wind farms.
Gravitational wave sources and data analysis
Authors: Owen Benjamin
Published: November 2017

What we look for affects how we look for it. I summarize current and predicted sources of gravitational waves, how the physics affects the signals, and how the signal morphologies affect analysis techniques. Expecting long and short signals, well modeled signals and unknown signals, means that gravitational waves use a variety of techniques familiar from acoustics, from matched filtering to wavelets and cross-correlation of data streams. These tell us today about black holes, and one day will tell us about neutron stars, cosmic explosions, and perhaps even stranger things.