bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct antiviral treatment of chronic hepatitis C in heart transplant recipients
Authors: Vitrone Martina , Andini Roberto , Mattucci Irene , Maiello Ciro , Atripaldi Luigi , Durante‐Mangoni Emanuele , Zampino Rosa
Published: November 2017

Direct‐acting antiviral agents (DAAs) are a safe and effective treatment for chronic hepatitis C (CHC). This may be particularly valuable for patients with severe comorbidities or baseline conditions, including non‐liver solid organ transplant. We report cases of two heart transplant recipients with CHC treated with DAAs (sofosbuvir and daclatasvir) achieving sustained virological response. Treatment was well tolerated and no relevant side effects were observed. The drug‐drug interactions and graft function were carefully monitored.
Cuestionario breve de juego patológico en estudiantes colombianos: propiedades psicométricas
Authors: Ruiz Pérez José Ignacio , Echeburua Enrique
Published: November 2017

El objetivo de este trabajo fue obtener las propiedades psicométricas del Cuestionario Breve de Juego Patológico (CBJP, Fernández-Montalvo, Echeburúa y Báez, 1995), así como determinar la prevalencia de probable juego patológico en una muestra no aleatoria (n=5858) de estudiantes de formación superior de todas las ciudades capital de Colombia. El CBJP mostró una fiabilidad interna aceptable y validez convergente con una medida de distorsiones cognitivas sobre los juegos de azar. La prevalencia de posibles problemas de adicción al juego fue similar a la encontrada con instrumentos más amplios en población análoga, y dicha prevalencia fue más alta en hombres, en personas más jóvenes y de nivel socioeconómico más bajo.
Calidad de vida y competencias sociales: un estudio comparativo entre adolescentes nativos e inmigrantes de España y Portugal
Authors: Romero Oliva Cristina , Nunes Cristina , Montilla Coronado Cecilia , Lemos Ida , Hernando Ángel , Ayala-Nunes Lara
Published: November 2017

Esta investigación pretende conocer las relaciones entre las competencias sociales y la Calidad de Vida (CdV) de los adolescentes nativos e inmigrantes de España y Portugal, para analizar la importancia que tienen estas variables en el desarrollo ajustado adolescente. Para ello, se evaluaron a 1151 adolescentes, con edades entre los 12 y 18 años, a través de dos cuestionarios: el KIDSCREEN-52 y Social Skills Rating System (SSRS). Los resultados señalan que los inmigrantes presentan un índice de CdV menor que los nativos en las dimensiones de Bienestar psicológico, Relación con los padres, Recursos económicos y Aceptación Social. El rendimiento académico correlaciona con las dimensiones de CdV y con las competencias sociales aunque existen diferencias entre los adolescentes nativos e inmigrantes.
Inteligencias múltiples y su relación con inteligencias cognitiva y emocional en adolescentes
Authors: Cejudo Javier , Losada Lidia , Pérez-González Juan Carlos
Published: November 2017

A partir del Inventario de Autoeficacia para Inteligencias Múltiples (IAMI), desarrollado en Argentina por Pérez, Beltramino y Cupani (2003), presentamos una adaptación abreviada para adolescentes españoles (IAMI-M40). IAMI evalúa la autoeficacia que los adolescentes tienen sobre las distintas inteligencias múltiples (IIMM) propuestas por Gardner (1999). En una muestra de estudiantes españoles de educación secundaria de 11 a 19 años (n=313), se evaluó su inteligencia fluida (PMA-R), cristalizada (16-PF-R), y emocional (TEIQue-ASF), y su nivel de IIMM mediante una adaptación española. El análisis factorial exploratorio de la adaptación española identificó ocho factores correspondientes a cada tipo de inteligencia del modelo de Gardner (1999), reteniendo 40 ítems de los 69 originales. Los resultados avalan la fiabilidad y la validez convergente del IAMI-M40.
Perfiles de orientación hacia la meta y su relación con indicadores de actividad físico-deportiva
Authors: De la Torre-Cruz Manuel J , Ruiz-Ariza Alberto , Ocaña-Expósito Sara , Martínez-López Emilio J
Published: November 2017

El presente estudio examinó la motivación hacia la actividad física empleando la teoría de la orientación hacia la meta. Un total de 786 estudiantes participaron en este estudio. Un procedimiento de análisis de cluster jerárquico permitió identificar cuatro perfiles de orientación hacia la meta. El perfil más adaptativo (alta tarea/alto ego/altas expectativas) se asoció con la obtención de los mejores resultados. Se concluye que los jóvenes con una alta motivación hacia la tarea, ego, y expectativas de ejecución obtienen las mayores muestras de apoyo por parte de familiares e iguales para la práctica de actividad física, se perciben más autoeficaces para realizar dicha actividad, se atribuyen una mejor forma física autopercibida, y manifiestan una práctica más frecuente de actividad físico-deportiva.
Egress Interaction Through Turbine Rim Seals
Authors: Scobie James A. , Hualca Fabian P. , Sangan Carl M. , Lock Gary D.
Published: November 2017

Engine designers require accurate predictions of ingestion (or ingress) principally caused by circumferential pressure asymmetry in the mainstream annulus. Cooling air systems provide purge flow designed to limit metal temperatures and protect vulnerable components from the hot gases which would otherwise be entrained into disk cavities through clearances between rotating and static disks. Rim seals are fitted at the periphery of these disks to minimize purge. The mixing between the efflux of purge (or egress) and the mainstream gases near the hub end-wall results in a deterioration of aerodynamic performance. This paper presents experimental results using a turbine test rig with wheel-spaces upstream and downstream of a rotor disk. Ingress and egress was quantified using a CO2 concentration probe, with seeding injected into the upstream and downstream sealing flows. The probe measurements have identified an outer region in the wheel-space and confirmed the expected flow structure. For the first time, asymmetric variations of concentration have been shown to penetrate through the seal clearance and the outer portion of the wheel-space between the disks. For a given flow coefficient in the annulus, the concentration profiles were invariant with rotational Reynolds number. The measurements also reveal that the egress provides a film-cooling benefit on the vane and rotor platforms. Further, these measurements provide unprecedented insight into the flow interaction and provide quantitative data for computational fluid dynamics (CFD) validation, which should help to reduce the use of purge and improve engine efficiency.
Testing of a Novel Post Combustion Acid Removal Process for the Direct-Fired, Oxy-Combustion Allam Cycle Power Generation System
Authors: Lu Xijia , Martin Scott , McGroddy Mike , Swanson Mike , Stanislowski Josh , Laumb Jason D.
Published: November 2017

The Allam Cycle is a high-performance oxy-fuel, supercritical CO2 power cycle that offers significant benefits over traditional fossil and hydrocarbon fuel-based power generation systems. A major benefit arises in the elimination of costly precombustion acid gas removal (AGR) for sulfur- (SOx) and nitrogen-based (NOx) impurities by utilizing a novel downstream cleanup process that utilizes NOx first as a gas phase catalyst to effect SOx oxidation, followed by NOx removal. The basic reactions required for this process, which have been well demonstrated in several facilities for the cleanup of exhaust gasses, ultimately convert SOx and NOx species to sulfuric, nitric, and nitrous acids for removal from the supercritical CO2 stream. The process results in simplified and significantly lower cost removal of these species and utilizes conditions inherent to the Allam Cycle that are ideally suited to facilitate this process. 8 Rivers Capital and the Energy & Environmental Research Center (EERC), supported by the state of North Dakota, the U.S. Department of Energy and an Industrial consortium from the State of North Dakota, are currently working together to test and optimize this novel impurity removal process for pressurized, semi-closed supercritical CO2 cycles, such as the Allam Cycle. Both reaction kinetic modeling and on-site testing have been completed. Initial results show that both SOx and NOx can be substantially removed from CO2-rich exhaust gas containing excess oxygen under 20 bar operating pressure utilizing a simple packed spray column. Sensitivity of the removal rate to the concentration of oxygen and NOx was investigated. Follow-on work will focus on system optimization to improve removal efficiency and removal control, to minimize metallurgy and corrosion risks from handling concentrated acids, and to reduce overall capital cost and operating cost of the system.
Experimental Investigation of Turbine Stage Flow Field and Performance at Varying Cavity Purge Rates and Operating Speeds
Authors: Dahlqvist Johan , Fridh Jens
Published: November 2017

The aspect of hub cavity purge has been investigated in a high-pressure axial low-reaction turbine stage. The cavity purge is an important part of the secondary air system, used to isolate the cavities below the hub level from the hot main annulus flow. A full-scale cold-flow experimental rig featuring a rotating stage was used in the investigation, quantifying main annulus flow field impact with respect to purge flow rate as it was injected upstream of the rotor. Five operating speeds were investigated of which three with respect to purge flow, namely, a high loading design case, and two high-speed points encompassing the peak efficiency. At each of these operating speeds, the amount of purge flow was varied from 0% to 2%. Observing the effect of the purge rate on measurement plane averaged parameters, a minor flow angle decrease and Mach number increase is seen for the low speed case, while maintaining near constant values for the higher operating speeds. The prominent effect due to purge is seen in the efficiency, showing a linear sensitivity to purge of 1.3%-points for every 1% of added purge flow for the investigated speeds. While spatial average values of flow angle and Mach number are essentially unaffected by purge injection, important spanwise variations are observed and highlighted. The secondary flow structure is strengthened in the hub region, leading to a generally increased over-turning and lowered flow velocity. Meanwhile, the added volume flow through the rotor leads to higher outlet flow velocities visible at higher span, with associated decreased turning. A radial efficiency distribution is utilized, showing negative impact through span heights from 15% to 70%. Pitchwise variation of investigated flow parameters is significantly influenced by purge flow, making this a parameter to include for instance when evaluating benefits of stator clocking positions.
Coupling of Creases and Shells
Authors: Wang Wei , Qiu Xinming
Published: November 2017

In the analysis of origami structures, the deformation of shells usually couples with the rotation of creases, which leads to the difficulty of solving high-order differential equations. In this study, first the deformation of creased shell is solved analytically. Then, an approximation method named virtual crease method (VCM) is employed, where virtual creases are used to approximate the deformation of shells, and then a complex structure can be simplified into rigid shells connected by real and virtual creases. Then, VCM is used to analyze the large deflection of shells as well as the bistable states of origami structures, such as single creased shell and cell of Miura-Ori. Compared with experiment results, the deformed states given by VCM are quite accurate. Therefore, this generalized method may have potential applications in the analysis of origami structures.
Tailoring nanopore formation in atomic layer deposited ultrathin films
Authors: Karwal Saurabh , Li Tao , Yanguas-Gil Angel , Canlas Christian P. , Lei Yu , Mane Anil U. , Libera Joseph A. , Seifert Soenke , Winans Randall E. , Elam Jeffrey W.
Published: November 2017

Selectivity is a critical attribute of catalysts used in manufacturing of essential and fine chemicals. An excellent way to induce selectivity in catalysts is by using ultrathin films with tailored nanoporosity. For instance, nanopores can be created in atomic layer deposition (ALD) ultrathin over-coatings on supported metal nanoparticles by subjecting the coatings to high temperature annealing. These nanopores expose the active surface of the underlying metal nanoparticles. The dimensions of these nanopores can be tuned to impart shape selectivity: only reactants or products with a specific size or shape can fit inside the pore. In this work, the authors explore the underlying mechanism driving nanopore formation in ALD films. Ultrathin films of ALD TiO2 (∼2.5 nm thick) and ALD Al2O3 (∼4.9 nm thick) were deposited on nonporous γ-Al2O3 nanoparticles. The pore formation and evolution were monitored in situ during thermal annealing using small-angle x-ray scattering (SAXS), and the crystallinity was monitored by in situ x-ray diffraction. A correlation between the nanopore formation and amorphous to crystalline phase transitions in the ALD layers was observed. The authors hypothesize that the pores form through the relaxation of stress induced by densification of the ALD films during the phase transitions. The authors developed a mathematical model to evaluate this hypothesis and found remarkable agreement between the model and the SAXS measurements.
Noise assessment for residential developments near places of entertainment in San Francisco
Authors: Roberts Jordan L.
Published: November 2017

When new multi-family residential developments are proposed in San Francisco, the City’s Entertainment Commission identifies whether there are places of entertainment (POE) within 300 feet. A POE includes businesses such as music venues, clubs, and bars. The Commission’s goal is to reduce complaints from new nearby residents about noise generated by existing entertainment venues. If there are too many complaints, a POE might be forced to close its business, which would have a negative impact on the City’s various entertainment districts. This assessment addresses noise that is distinct from the noise associated with a typical environmental noise study (which addresses noise from street traffic, rail activity, etc.). Rather than put the onus on existing businesses, the housing developer is asked to consider bass-heavy nighttime noise sources that future residents could perceive. Thus, some facades of proposed buildings might need to provide greater noise reduction than typical construction, often times through increased window STC rating recommendations. The measurements, calculations, and mitigations of these assessments are to be presented through select data from multiple case studies.
The sounds of submarine volcanoes
Authors: Tepp Gabrielle , Haney Matthew , Lyons John , Dziak Robert , Haxel Joe , Bohnenstiehl Del , Chadwick William
Published: November 2017

When submarine volcanoes erupt, several processes can create sounds in the ocean, mostly at low frequencies <100 Hz. Explosions may occur directly in the water column, while earthquakes and other seismicity may produce seismic waves that convert into hydroacoustic waves or boundary (Scholte) waves. Volcanic sounds can propagate large distances through the SOFAR channel. During its 2014 eruption, Ahyi seamount, Northern Mariana Islands produced repetitive signals for approximately 2 weeks at a high rate. These likely explosions were widely recorded on seismometers throughout the region and on hydrophone arrays as far as Chile, ∼12,000 km distant. Bogoslof volcano, a shallow submarine volcano in the Aleutian Islands, Alaska, began erupting in December 2016. Many of the detected earthquakes associated with this eruption have large amplitude hydroacoustic phases, likely Scholte waves. A few earthquake swarms were recorded as converted hydroacoustic waves by seismometers on Tanaga volcano, ∼700 km away. A few eruption sequences were also detected on the Tanaga stations, one of which included a monochromatic glide, suggesting efficient transmission of energy into the water column. A single hydrophone deployed near Bogoslof several months after the eruption began may add evidence for how eruptions of submarine volcanoes contribute to the underwater soundscape.
Full-field laser vibrometer study of dissipation in a beam with a coupled oscillator array
Authors: Gietl Jenna , Sterling John A. , Ryan Teresa J. , Vignola Joseph F. , Turo Diego
Published: November 2017

Coupled oscillator systems can be designed to manage the distribution of mechanical energy in vibration or acoustic systems. A specific implementation of an array composed of small damped mass-spring attachments on a primary is here referred to as a subordinate oscillator array. SOAs and their ability to absorb energy from a primary mass are of continued importance in analysis for both structural and acoustic systems. The ability to dissipate energy in a specific frequency band has many potential applications. This work will use laser Doppler vibrometry (LDV) to evaluate a beam mounted on an electromechanical shaker with and without an attached planar SOA composed of much smaller beams. This study is motivated by earlier work that indicated a high sensitivity to disorder in the form of fabrication error. The apparatus allows for the controlled introduction of various levels of disorder to quantify its effect and compare to a numerical model. We will show full-field forced response from the LDV with and without the SOA and the resulting apparent damping within the band of the SOA for various levels of disorder.
Investigation of single and twin jet interactions with plates with cut-outs
Authors: Natarajan Karthikeyan , Venkatakrishnan Lakshmi
Published: November 2017

The design and testing of the launch vehicle structure and its subsystems to withstand the lift-off acoustic loads is quite a daunting task in itself. Any effort to minimize these loads can prove to be highly beneficial as it directly influences the design, weight, and qualification of the launch vehicle components and hence the overall vehicle operating cost and time. The components of launch pad such as the launch platform and jet blast deflector are known to be the principal noise sources of the intense acoustic loads generated during lift-off. They contribute to the overall noise levels experienced by the launch vehicle by either reflecting the noise generated by the jet exhaust or by creating additional sources of noise. Earlier studies showed that the presence of cut-outs in the launch platform significantly affects the overall acoustic loads experienced by the launch vehicle. The present paper attempts to characterize the influence of cut-outs in the launch platform on the noise levels experienced by the launch vehicle, by investigating single and twin jets impinging on flat plates with and without cut-outs at varying lift-off distances. The results from acoustic measurements carried out in the near and far-field of scaled down single and twin jet launch vehicle models are discussed. The paper also attempts to relate changes in acoustic field, brought about by the different platform configurations, to the changes in flow field through flow visualization using the schlieren technique.
Development of a rating of the improvement of high-frequency impact noise
Authors: LoVerde John , Dong David W.
Published: November 2017

The authors have introduced a family of new impact noise isolation ratings for evaluating high-frequency impact sound, which encompasses the frequency range of 400-3150 Hz. The advantages of this rating include better correlation with subjective reaction and improved rank-ordering of finish flooring and sound mats. A natural extension of this metric is to define a rating of the improvement in impact isolation analogous to ΔIIC per ASTM E2179. The resulting metric ΔHIIC evaluates the improvement in high-frequency impact isolation due to floor coverings as measured in the laboratory. The research indicates that ΔHIIC predicts the result due to floor coverings considerably better than ΔIIC. Potential applications of the rating for the design and evaluation of floor-ceiling assemblies is presented.
Methods for calculating flanking noise transmission
Authors: Dong David W. , LoVerde John
Published: November 2017

Airborne sound isolation between spaces is determined not only by the direct sound transmission through the separating assembly, but also flanking transmission, which is the structureborne transmission of vibration due to acoustical excitation in the source room. In many cases, the flanking paths dominate, such as where the separating assembly has a high level of sound transmission loss, and the ability to calculate these paths is therefore crucial if the isolation is to be accurately predicted. Methods for calculating impact noise have been developed in Europe [standard EN ISO 12354] and are currently in use in Europe and Canada; however, the methods are not commonly known or used in the United States. The authors report on use of these methods in calculating flanking noise transmission in recent projects.
An autonomous, bottom-mounted sonar for measurement of mid-frequency reverberation
Authors: Hefner Brian T. , Tang Dajun , Shim Taebo
Published: November 2017

While bottom reverberation is typically dominant over surface reverberation at mid-frequencies in shallow water, sea surface roughness has a significant impact on transmission loss and hence on reverberation. Measurements of this effect can be difficult with a system deployed from a moving ship due to both the system motion and the constraints of operating the ship safely in the rough seas of interest. To overcome these difficulties, the Autonomous Reverberation Measurement System (ARMS) has been developed under an ONR-sponsored DURIP. This system is a benthic lander with a directional source and receive array mounted on a rotation stage. Powered by batteries and programmed prior to deployment, the system can measure reverberation from 2-6 kHz as a function of direction autonomously for up to 3 months. This system was deployed in the spring of 2017 as part of an experiment conducted off Geoje Island, Republic of Korea. During this experiment, the ARMS was deployed in 28 m of water and measured reverberation in a muddy sand environment with a range-dependent water depth that was punctuated with rock outcroppings on the seafloor. [Work supported by the U.S. Office of Naval Research.]
Progress on applying the small-slope approximation to layered seafloors
Authors: Jackson Darrell
Published: November 2017

The small-slope approximation (SSA) for scattering by rough interfaces is an attractive alternative to the classic small-perturbation and Kirchhoff approximations, as it combines the best aspects of both and may be more accurate over all angular ranges. While SSA has most frequently been applied to impenetrable interfaces and interfaces bounding homogeneous half spaces, it has also been developed for layered media. There is no unique extension of SSA to layered media, and three different methods have appeared in the acoustics and electromagnetics literature. These methods will be reviewed and a new, possibly superior, method will be introduced. This method arises naturally when SSA is expressed in coordinate space rather than k-space. The various methods will be compared using numerical examples. [Work supported by ONR.]
Late backscattering enhancement from a rubber spherical shell associated with waveguide coupling and propagation
Authors: Gunderson Aaron M. , Daniel Timothy , Marston Philip L. , Isakson Marcia J.
Published: November 2017

Acoustic scattering from rubber targets has received modest attention in the past due in part to rubber’s subsonic sound speeds. In particular, slow shear waves in rubber get rapidly attenuated, giving rubber the fluid-like property of negligible shear coupling. This makes rubber a material of interest for coating or cloaking underwater objects and vehicles. In this study, backscatter from a rubber spherical shell in water is considered experimentally and through such models as partial wave series, finite elements, and waveguide normal mode analysis. The target is a commercially available American handball of unspecified rubber composition. Experimental and modeled results exhibit the importance of a strong, slightly subsonic late echo, which is demonstrated through path timing models and frequency analysis to be due to waveguide propagation through the shell wall. The various models use wave speeds for the rubber determined experimentally, allowing for determination of the phase and group velocities of the lowest order waveguide mode within the shell. These are found through normal mode analysis for both flat and curved waveguides, and again through Sommerfeld-Watson theory. Frequency domain results show how the waveguide path interferes with reflective paths from the shell in a frequency-dependent manner. [Work supported by ONR.]
Review of the perception of diffusive surfaces in architectural spaces
Authors: D'Antonio Peter , Madison Jeffrey , Cox Trevor J.
Published: November 2017

The use of sound diffusors started in antiquity in the form of statuary, balustrades, coffered ceilings, and surface ornamentation. While these surfaces added both beauty and useful scattering, their bandwidth was limited. It was not until the invention of the reflection phase grating by Manfred Schroeder in 1973 that acousticians were able to design number theoretic surfaces with a specified broad bandwidth. Later Cox and D’Antonio expanded diffusive design options beyond number theoretic surfaces to include fractal surfaces, binary amplitude diffusors and beautiful curvilinear architectural shapes acceptable to the architectural community, using shape optimization software. Many peer review publications and books by the authors, ushered in the widespread use of sound diffusion to complement sound absorption. Significant research ensued to study various shapes, bandwidth, location, coverage, and their perceptual aspects. This presentation will review how sound diffusion modified the sound fields originally in recording control rooms, followed by home theaters, rehearsal spaces, performance stages and auditoria, worship spaces, and sound reproduction spaces. Many applications will be presented, as well as subjective questionnaires and objective measures.
Distinguishing between varying amounts of diffusion subjectively and objectively
Authors: Bliefnick Jay , Wang Lily M.
Published: November 2017

This paper summarizes findings from a study of both subjective perception and objective quantification of varying amounts of diffusion. Numerous impulse response measurements were collected from a physical acoustics testing facility that featured reversible absorptive/diffusive/reflective wall panels. The collected room impulse response measurements were utilized in subjective perception trials as well as an objective metric analysis. Subjective testing used auralizations from the measured impulse responses in audio comparison trials to determine how well diffusive room conditions could be discerned. It was found that more than 50% coverage of diffusive surface area was required for the average subject to discriminate between diffusive and absorptive wall conditions. Subjects were even less capable of discerning between diffusive and reflective wall conditions. The objective metric analysis identified the Number of Peaks methodology as the most effective metric for assessing diffusive room conditions from amongst those tested.
Characterization of diverse coral types using passive acoustic recorded data from the lagoon area of the Kavaratti—An atoll of the Lakshadweep archipelago
Authors: Chakraborty Bishwajit , Chanda Kranthi Kumar , Madhusudhana Shyam Kumar
Published: November 2017

The presence of sound in marine habitats can be an indicator of biological processes. Therefore, sound monitoring of the reef system is important to develop an in-depth understanding of the biodiversity, vulnerabilities, and potential changes of ecosystems. In order to understand the diversity related to the coral types, we have computed Acoustic Complexity Index (ACI) (temporal and spectral scales) using passive acoustic recorded data from the lagoon area off the Kavaratti—an atoll of the Lakshadweep archipelago. ACI is found to be the highest in location “A” where the coral type of Acropora sp. and ample fish diversity is observed. In location “C” where massive Porites sp. and Pocillopora sp. with significant acoustic assemblages are observed, ACI was found to be comparatively lower than the location “A.” Whereas for “B,” “D,” and “E” locations, relatively low level of ACI index is obtained. The ACI is the lowest in location “B” where macroalgae with no fish species are seen. Among these three locations, “E” shows higher ACI due to the shrimp sound dominance in the rock substrate having Porite sp. coral type.
Contemporary distribution of the eastern North Pacific right whale in the Bering Sea
Authors: Wright Dana , Crance Jessica , Woodrich Daniel , Brewer Arial , Berchok Catherine L.
Published: November 2017

The eastern population of the critically endangered North Pacific right whale (NPRW; Eubalaena japonica) historically ranged in the eastern Bering Sea from the Aleutian Islands to St. Matthew Island (60.4°N), with limited (n < 20) detections further north (which some consider bowhead whale; Balaena mysticetus). Since the 1980s, most NPRW sightings have been isolated to the southeastern Bering Sea. In order to describe the current spatio-temporal distribution of NPRW, long-term passive acoustic recorders throughout the Bering Sea (2012–2016) were analyzed manually (10,204.2 days; 27–29% duty cycle) for the presence of NPRW, which were identified using the “up” and “gunshot” calls. NPRW were consistently detected during ice-free months in the southeastern Bering Sea, and intermittently during the same months northward to 59°N. NPRW were also detected at low calling activity within two eastern Aleutian Passes. Notably, NPRW were detected north of St. Matthew (61.6°N) in summer 2016 (July–Aug.). Up and gunshot calls north of 62°N in ice-free months and north of 58°N in ice-associated months could not be distinguished from bowhead whale. Together, these results indicate that NPRW currently range with certainty from the eastern Aleutian Passes to 61.6°N, but may range as far north as the Bering Strait.
Evidence of low-frequency multiple scattering of methane gas bubbles at Coal Oil Point, Santa Barbara, California
Authors: Padilla Alexandra M. , Loranger Scott , Weber Thomas C.
Published: November 2017

Coal Oil Point, located in the Santa Barbara Channel, CA, is known for its prolific natural hydrocarbon seepage. These hydrocarbons are released at depths between 30 and 80 m, shallow enough that the hydrocarbons reach the surface. Transport via bubbles and droplets through the water column enables the exchange of hydrocarbons between the ocean and the atmosphere. Hydroacoustic observations from previous surveys have been used to map hydrocarbon seep distributions and estimate the flux of hydrocarbons from the seafloor in Coal Oil Point. On September 14, 2016, this area was revisited and surveyed using low-frequency sub-bottom profilers operating from 1 to 10 kHz. The goal is to estimate the gas flux of hydrocarbons from the hydroacoustic measurements and compare them to historic estimates for this area. Visual observations of dense bubble cloud structures of these seeps were seen and evidence of multiple scattering effects were observed in the hydroacoustic measurements. We examine how acoustic scattering of natural hydrocarbon gas bubbles is effected by multiple scattering and how this process affects the quantification of gas flux.
A study on a friendly automobile klaxon production with rhythm
Authors: Jee SangHwi , Kim Myungsook , Bae Myungjin
Published: November 2017

We are always exposed to traffic noise in our lives. Especially in unproven situations, exposure to a sudden sound may result in loss of auditory cells and exposure to retaliatory driving. However, if you do not use horn sounds, you will not be free from traffic accidents when driving. The Clackson is used as a car horn and has a simple mechanical structure, which is easy to use. However, it has a disadvantage that it can not redesign the sound pressure of fluid sound. In this study, the power supply time width of Clackson was adjusted to five (0.01 s, 0.02 s, 0.03s, 0.06 s, and 0.13 s). The result was a sound level of five (80 dB, 85 dB, 90 dB, 100 dB, and 110 dB) sound levels of the Klaxon. The experimental result shows that the maximum sound pressure (pmax = 110 dB) after operating the clackson is tmax. Ps (dB) = 110 (dB)—{10log (ton / (ton + toff)) + 20log (ton / tmax) The preference was evaluated for five types of Clackson sounds of 5 seconds. The MOS evaluation was performed on 100 participants after three times of five kinds of Klaxon sounds. The evaluation items were MOS measurement for risk, sound size, unpleasantness, and stress. As a result of evaluation, when designing various forms of clackson sound, it was quickly felt that it is danger to give a sound rhythm to a horn sound rather than a conventional sound. In particular, if you change the rhythm of the sound of Klaxon, the risk perception becomes faster even though the average sound level is lowered by −20 dB.
Timbre of marching-band brass instruments
Authors: Pyle Robert W. , Klaus Sabine , Myers Arnold
Published: November 2017

The tone quality of brass instruments for outdoor use has varied from time to time and from place to place. Instruments currently in use can be recorded and analyzed. However, many older instruments, typically those in museum collections, are not allowed to be played. Hence, it is necessary to rely on measurements of physical dimensions and acoustic input impedance to form comparisons. In this paper, such measurements are used to estimate two important timbral parameters: the spectral centroid at moderate playing levels and the brassiness potential. For different instruments of the same pitch, like trumpet and flugelhorn, the spectral centroid gives a measure of the brightness or darkness of the tone. The brassiness potential gives a measure of the degree to which the tone develops a “brassy” edge at high playing levels. As one might expect, the trumpet has both a higher spectral centroid and a higher brassiness potential than the flugelhorn. Results will be shown comparing instruments built in different countries and at different times.
Acoustics, performance, and instrument invention at Cyclophonica Bicycle Orchestra
Authors: Fuks Leonardo
Published: November 2017

Cyclophonica Bicycle Orchestra was created in 1999 in Rio de Janeiro- Brazil by the present author as a platform for experimenting new ways of music making, developing new instruments and techniques. Inspired by the traditional marching and animal-mounted bands, present all over the world, the project of Cyclophonica aimed at exploring open-air or closed ambients, involving or moving with the audience and being able to control “chamber” music performance and instruments, while ensuring safety to the players and listeners. Several questions were still open: which were the instruments that could be played?; would musicians be able to accelerate the tempo and reduce the bicycle speed independently?; how well would the performers coordinate music without a conductor or looking to each other?; how would the listeners receive such music that would be produced and diffused in a different way? A group of six musicians was formed in the beginning. Presently, after more than eighteen years later, the Cyclophonica has ten fixed members and two additional ones, and has performed more than two hundred and fifty times, in different festivals, events, and official ceremonies, almost always being paid for, being perhaps the only professional group of this kind in the world.
Spatiotemporal analysis of high-performance military aircraft noise during ground run-up
Authors: Swift S. Hales , Gee Kent L. , Neilsen Tracianne B. , Wall Alan T. , Downing Micah , James Michael M.
Published: November 2017

Recent measurements of high-performance military aircraft noise have revealed that full-scale jet noise has features and structures that are still only partly understood, such as the presence of multiple acoustic radiation lobes in the aft direction at certain frequencies. Spatiotemporal analyses of a ground-based microphone array measurement of the noise from a tethered F-35 at various engine conditions are used to investigate these features of the sound field. The ground array covered an angular aperture of 35–152 degrees relative to the front of the aircraft. The large angular aperture allows for a detailed investigation of the correlation and coherence at frequencies exhibiting multi-lobe behavior. This spatiotemporal analysis yields further evidence of the characteristics of multi-lobe behavior in high-performance, full-scale jet noise. [Work supported by an Office of Naval Research grant, a USAFRL SBIR, and the F-35 JPO. Distribution A: Approved for public release; distribution unlimited. Cleared 07/10/2017; JSF17-714.]
Characterization of broadband shock-associated noise from high-performance military aircraft
Authors: Neilsen Tracianne B. , Vaughn Aaron , Gee Kent L. , Wall Alan T. , Downing Micah , James Michael M.
Published: November 2017

For nonideally expanded jets, broadband shock-associated noise (BBSAN) is a feature in the sideline and forward directions. While BBSAN has been studied fairly extensively for laboratory-scale jets, its presence and characteristics in full-scale, tactical aircraft noise need to be evaluated. Noise measurements on a tied-down F-35 provide the opportunity to characterize full-scale BBSAN using a linear ground array that spanned a large angular aperture: 35–152 degrees relative to the front of the aircraft. The main questions are whether the full-scale BBSAN shares the same characteristics as those observed in laboratory-scale BBSAN and if current models capture the features of full-scale BBSAN. The variation in the spectral shape, peak frequency, and peak level of full-scale BBSAN across angle for different engine powers is explored and compared to prior laboratory studies. Comparisons are also made with models for BBSAN based on stochastic theory ([Tam et al., J. Sound Vib. 140, 55–71 (1990)]) and the simplified model used in Kuo et al. [AIAA Paper 2011–1032 (2011)] for lab-scale BBSAN. Frequency-dependent convective speed estimates obtained from the current BBSAN models are compared to estimates based on directivity. [Work supported by the Office of Naval Research and the F-35 JPO.]
Calculating the frequency-dependent apparent source location using peak cross-correlation between near-field and far-field microphone arrays
Authors: Ward Jacob A. , Swift S. Hales , Gee Kent L. , Neilsen Tracianne B. , Okamoto Koji , Akamine Masahito
Published: November 2017

The apparent acoustic source region of jet noise varies as a function of frequency. In this study, the variation of the apparent maximum source location with frequency is considered for an ideally expanded, unheated, Mach-1.8 jet with exit diameter of 20 mm and a Reynolds number of 6.58e6. In this study, the source location is ascertained for one-third octave bands by evaluating peak cross-correlation between near-field linear microphone arrays at three sideline distances and a far-field microphone arc. The impact of the hydrodynamic field on correlation results is considered. Source locations determined by these means are compared with intensity analyses for the same jet [K. L. Gee et al., AIAA Paper 2017–3519 (2017)]. Correlational methods together with filtering can provide a straightforward measure of the acoustic origin as a function of frequency and thus inform optimal microphone array layout for specific frequency regimes.
Numerical validation of using multisource statistically optimized near-field acoustical holography in the vicinity of a high performance military aircraft
Authors: Leete Kevin M. , Wall Alan T. , Gee Kent L. , Neilsen Tracianne B. , Downing Micah , James Michael M.
Published: November 2017

Multisource statistically optimized nearfield acoustical holography (M-SONAH) is an advanced holography technique [Wall et al., J. Acoust. Soc. Am. 137, 963–975 (2015)] that has been used to reconstruct the acoustic field from measurements taken in the vicinity of a high-performance military aircraft [Wall et al. 139, 1938 (2016)]. The implementation of M-SONAH for tactical jet noise relies on creating an equivalent wave model using two cylindrical sources, one along the jet centerline and one below the ground as an image source, to represent the field surrounding an aircraft tethered to a reflecting ground run up pad. In this study, the spatial and frequency limitations of using the M-SONAH method to describe the field of a tethered F-35 is explored by using the same measurement geometry as at a recent test, but substituting the sound field obtained from a numerical source for the measurement data. The M-SONAH reconstructions are then compared to numerical benchmarks. A spatial region and frequency bandwidth where bias errors are low are identified and provide validation for the use of this method in tactical jet noise source and field reconstructions. [Work supported by USAFRL through ORISE and the F-35 JPO. Distribution A: Approved for public release; distribution unlimited. Cleared 07/10/2017; JSF17-714.]
Sound quality analysis of far-field noise from a high-performance military aircraft
Authors: Swift S. Hales , Gee Kent L. , Neilsen Tracianne B. , Wall Alan T. , Downing Micah , James Michael M.
Published: November 2017

Noise from high-performance military aircraft can pose challenges to community relations near airfields. Accurately predicting and quantifying community impacts is important for efforts to minimize such impacts and reduce annoyance. In this study, sound recordings measured 305 m from a tethered F-35 aircraft operating at various engine conditions are analyzed using sound quality metrics. The calculated metrics are inputs for a model of perceived annoyance used to estimate the relative contributions of loudness and other sound quality features to annoyance. These results can help inform future efforts at noise reduction by identifying potentially relevant sound quality components of the jet noise as well as helping inform discussions of noise policy on military bases. [Work supported by a USAFRL SBIR and the F-35 JPO. Distribution A: Approved for public release; distribution unlimited. Cleared 07/10/2017; JSF17-714.]
Prediction of ground-borne vibrations due to elevated railway traffic
Authors: Alan Salih , Caliskan Mehmet
Published: November 2017

This study investigates the impact of ground-borne vibrations on people in dwellings nearby elevated railway traffic. Assessments are conducted over predicted vibrations with respect to national regulations. Main excitation mechanism is taken as the dynamic loading due to rail and wheel irregularities. Frequency response functions at the rail head are obtained from harmonic analyses by finite element modeling of the elevated structure. In the prediction procedure, dynamic model of the vehicle is coupled with these frequency response functions. Dynamic loading on the railhead is determined and dynamic reaction forces on the legs of the elevated structure are calculated in frequency domain. Ground vibrations are then estimated by implementing a Fourier transform based theoretical model for the layered ground. Assessment in the frequency range from 1 Hz to 100 Hz in one-third octave bands are conducted for groundborne vibrations calculated at the foundation level of dwellings.
Towards a model of Tatar intonational phonology
Authors: Royer Adam J.
Published: November 2017

This study is a preliminary report of our ongoing research investigating an Autosegmental-Metrical model of intonational phonology of Kazan Tatar, a Turkic language spoken in Tatarstan, Russia. Tonal patterns of neutral focus utterances were examined by varying the length of words and phrases, the location of stresses, syntactic structures, and sentence types. Results suggest that Tatar has three prosodic units marked by intonation. They are the Accentual Phrase (AP), the Intermediate Phrase (ip), and the Intonational Phrase (IP). An AP has one or more words and has an optional initial high tone (Hi), realized at the left edge or leftmost stressed syllable of the AP, and an obligatory rising pitch accent (L + H*) aligned with the rightmost stressed syllable of the AP. Interestingly, the unstressed syllables after the pitch accented syllable show high f0 until the end of the AP, suggesting an optional AP-final H tone (Ha). An ip is marked by a phrase-final high tone (H-) realized on an ip-final syllable, which is slightly longer than AP-final syllable. Finally, an IP is marked by a phrase-final boundary tone realized on a substantially lengthened syllable. A fuller model of Tatar will be compared with the intonation models of other Turkic languages.
The nature of variation in the tone Sandhi patterns of Wuxi Wu
Authors: Yan Hanbo , Zhang Jie
Published: November 2017

The Northern Wu Chinese dialect of Wuxi has two different tone patterns in disyllables—a pattern with tone sandhi that involves a synchronic chain-shift and a no sandhi pattern, and the two patterns apply variably. This study investigates the nature of this variation. Seventy-one native speakers participated in three rating experiments that investigated disyllables “subjective frequency, semantic transparency, and the variant forms” perceptual goodness. Results show that modifier + noun combinations prefer the sandhi form more than verb + noun combinations. Lexical frequency has a positive effect on sandhi application in both modifier + noun and verb + noun items. Semantically transparent items are less likely to undergo tone sandhi, but only for verb + noun combinations. These results are interpreted with respect to the properties of wordhood in Wuxi and Chinese dialects in general and the productivity of the chain-shift tone sandhi pattern observed in an earlier production study.
Comparing roughness in sustained phonations and connected speech using a matching task
Authors: Anand Supraja , Eddins David A. , Shrivastav Rahul
Published: November 2017

Experiments on perception of dysphonic voice quality have typically relied on sustained vowel phonations. The strong preference for vowels could be explained by their ease of production, their time invariance, and by the absence of confounding articulatory (e.g., consonant, dialect) and prosodic (e.g., stress, rate) changes. However, the magnitude of roughness perceived from sustained vowels may not reflect the roughness in connected speech produced by the same speaker. We examined how stimulus type impacts the perception of roughness. Ten naïve listeners judged roughness for both vowel /a/ and sentences selected from ten dysphonic speakers using a single-variable matching task. Stimuli were selected to ensure a continuum of vocal roughness for vowels. The intra- and inter-listener reliability estimated using intra-class correlation (ICC) as well as matching values and variability will be compared across each stimulus type. This work is essential for extending models of dysphonic voice quality perception from vowels to connected speech, which are likely to correspond more closely with perceived handicap and better represent relevant treatment targets for patients with dysphonia.