bluuebunny/crossref_metadata_2025 huggingface dataset:
Passive detection and localization of marine mammals in the Ligurian Sea
Authors: D’Amico Angela , Bondaryk Joseph E. , Portunato Nicola
Published: July 2002

SACLANTCEN sponsored an environmental acoustic measurement in the Ligurian Sea in August 1999. The objectives of this cruise were to detect, localize and track marine mammals using passive acoustic techniques. During this cruise, the R.V. Alliance passively operated several advanced sonar arrays near Corsica. Acoustic techniques were used to localize and track several species of cetaceans in position and depth over time from their vocalizations only. The acoustic results are compared to ground truth provided by visual observations and data from several radio tags with time-depth recorders. Statistics on whale vocalizations and behavior are tabulated. At the time of this abstract submission, it is anticipated that data on Fin, Sperm and other cetaceans will be available.
The effect of age on vibrotactile adaptation
Authors: Goble Alan K.
Published: July 2002

The aging process is known to affect the processing of somatosensory information. For example, a number of recent studies have shown that detection thresholds for vibrotactile stimuli are elevated at low and high frequencies in elderly individuals, as compared to comparable measurements in young adults. The present study is the first to directly measure the effect of aging on vibrotactile adaptation. Detection thresholds for 25-Hz sinusoidal vibrations presented to the thenar eminence via a 5-mm-diameter contactor were measured in a small group of senior citizens (n=4) before and after exposure to a 25-Hz 20-dB SL adapting stimulus and compared to comparable measurements previously obtained on younger adults (n=4). As expected, baseline thresholds were significantly higher in the older observers by some 12 dB (p<0.0000). Furthermore, older individuals exhibited significantly less adaptation than their younger counterparts (71 vs 14.4 dB, p<0.0000). These results provide evidence of age-related changes in both peripheral and central nervous system function, and suggest directions for future research. [This research was supported by NIH Grant No. 2 S14 GM44780-08.]
Electrical bioimpedance monitoring of cardiovascular effects of noise
Authors: Belojevic Goran , Stojanov Vesna , Jakovljevic Branko , Ivanovic Jelena
Published: July 2002

Cardiovascular effects of recorded traffic noise (Leq=89 dBA) were monitored with an ‘‘AVL 2001’’ electrical bioimpedance apparatus on 12 medical students (4 male and 8 female), and compared to quiet conditions (Leq=40 dBA) before and 10 min after exposure. There were significant changes of the following cardiovascular parameters in quiet–noise–quiet conditions (Mean±SD): cardiac work/kgm/m2/(7.0±2.0; 6.4±1,5; 7,1±2,1; respectively; P<0.01, Friedman ANOVA test); global flow [L/min/m2] (5.8±2.0; 5.4±1,5; 6.0±2.0; respectively; P<0.01), pump output/beat [ml/m2] (75±26; 69±18; 78±21, respectively; P<0.05) and peripheral vascular resistance (afterload) [Ω m2] (1347±476; 1387±458; 1273±430; respectively; P<0.01). No significant effects of noise were observed concerning pulse frequency, systolic and diastolic arterial blood pressure, preload, pump efficiency, thoracic fluids, and contractility. These results indicate that intense noise has a strong vasoconstrictive effect, which in longer terms may lead to disturbances in the regulation of arterial blood pressure and in coronary circulation.
Differential ultrasonic stress–strain measurements
Authors: Hailu Sissay , Halford Gary R. , Hazony Dov , Welsch Gerhard
Published: July 2002

Fatigue tests are often encumbered by lack of the specimen’s exact length due to mechanical grip effects and by environmental noise factors. Such issues may be mitigated when differential measurements are undertaken between consecutive data states. Our principle-monitoring tool is an ultrasonic pulse-echo process where the primary and secondary echoes along the principle specimen’s axis provide both length and gage length, respectively [D. Hazony, Circuit Systems Signal Process. 14(4), 525–538 (1995)]. The process is also useful for crack detection [I. Mostafa et al., Int. J. Fracture 85, 99–109 (1997)]. Compared with absolute measurements, differential stress-strain monitoring is shown to be highly reproducible and more sensitive providing changes in Young’s modulus and Poisson’s ratio as well as a focus for the detection of an emerging crack. [Work supported by NASA.]
Profiling a surface using its echoes
Authors: Block Gareth , Harris John G.
Published: July 2002

The electromechanical reciprocity relation is used to construct a theoretical model of the imaging of a sinusoidal fluid–solid interface using a cylindrically focused acoustic beam. The electromechanical reciprocity relation is used to connect the change in the voltage measured at the electrical terminal of the transducer to the perturbation in the mechanical wave field caused by a change in the profile of the interface. It does so by mixing an unperturbed reference wave field with one containing the perturbed wave field. We use a regular boundary perturbation expansion to obtain an approximate boundary condition that fits directly into the reciprocity relation. This perturbation assumes both the amplitude and the slope of the profile are small. We limit our discussion to imaging a sinusoidal interface with the understanding that resolution of this profile is central to understanding that of more general profiles. We find that depending on the choice of parameter values the measured profile is not simply a replication of the original sinusoidal profile. Time permitting, we briefly indicate preliminary work on a related model of the imaging of the mechanical properties of a thin solid film using a confocal arrangement of point-focused transducers. [Work supported by NSF.]
Detection of fatigue crack initiation and growth in steel specimens from Rayleigh scattering of 5-MHz Rayleigh waves
Authors: Cook Daniel A. , Berthelot Yves H.
Published: July 2002

Detecting the formation of surface microcracks remains an important challenge for condition-based maintenance (CBM) and remaining life prediction algorithms. A relatively new method [see M. Resch and D. Nelson, ASTM STP 1149, 169–196 (1992)] consists of monitoring the reflection of pulsed surface waves off the crack. The method is extended to monitor the Rayleigh forward and backscattering (low-ka regime) with pulsed 5-MHz surface waves propagating on steel specimens under tensile cyclic loading. The cross-correlation of the received signals measured as a function of the number of fatigue cycles can be used to detect the presence and the growth of small cracks. Experimental results will be presented and discussed. [Work supported by the Office of Naval Research, N00014-95-1-0539, MURI Center for Integrated Diagnostics.]
A course in musical acoustics for nonengineering majors at the University of Hartford
Authors: Celmer Robert
Published: July 2002

The University of Hartford’s College of Engineering provides a service course entitled ‘‘Introduction to Musical and Architectural Acoustics’’ for nonengineering students majoring in such degree programs as music (at the Hartt School), technology fields, or the liberal arts. The material covers: acoustics terminology and concepts; a study of the science of each musical instrument family; sound radiation patterns of instruments and the implications for sound recording technology; the auditory system and hearing conservation; and an introduction to architectural acoustics related to such applications as band room and auditorium design. This presentation will describe some of the multi-media techniques for in-class presentation of the material as a means of better disseminating complex information using a sensory-rich environment. The extent to which this course fits into the assessment goals and general education science requirements of these nonengineering majors will also be discussed.
Voiced noise: The ‘‘heterogeneous sound ideal’’ as preferred acoustic environment in selective sub-Saharan African instruments and ensembles
Authors: Avorgbedor Daniel , Pyne James
Published: July 2002

This paper draws on the African–American composer Olly Wilson’s notion of a ‘‘heterogeneous sound ideal’’ in which the author discusses the common preference for certain sound combinations and timbres in African and African–American musical traditions. The purpose of this presentation is to demonstrate, in detail, specific aspects of this concept by drawing on a variety of instrumental and ensemble traditions from sub-Saharan Africa with focus on the manipulation and intentional modulation of timbres that characterize much of the musical traditions of sub-Saharan Africa and which are often overlooked by analysts. The paper argues that this common emphasis on ‘‘unusual’’ timbres constitutes one of the major parameters distinguishing sub-Saharan African musical traditions from those of European art music traditions. A ‘‘heterogeneous sound ideal’’ suggests new approaches to the identification, measurement, evaluation, and appreciation of acoustic phenomena in the contexts of sub-Saharan African musical traditions. Additional demonstrations involving spectral–timbral projections of individual and ensemble instruments will be presented.
An inverse structure for active noise control or combined active noise control/transaural sound reproduction
Authors: Quednau Stephan , Bouchard Martin
Published: July 2002

In this presentation, the use of inverse models of the acoustic plants is investigated for active noise control (ANC) systems. It is shown that the use of the inverse models combined with a predictor can: (1) greatly improve the convergence speed of stochastic gradient descent algorithms such as the multichannel filtered-X LMS or the modified filtered-X LMS and (2) significantly reduce the computational load of the resulting ANC system. Moreover, for systems combining active noise control and trans- aural sound reproduction (TSR), the reduction of the computational load will be even greater, since TSR systems implicitly need the use of the inverse models of the acoustic plants, and the proposed ANC inverse structure already performs this inverse filtering. For broadband feedforward ANC controllers, the drawback of using the typically noncausal inverse models of the acoustic plants is to increase the delay required between the reference signal(s) of the controller and the disturbance signal(s) to be reduced. In the case of feedback controllers, this additional delay would likely limit the application of the proposed structure to the control of periodic disturbances only.
Multichannel RLS algorithms and FTF algorithms for active noise control and sound reproduction systems
Authors: Bouchard Martin
Published: July 2002

In the fields of active noise control (ANC) and transaural sound reproduction (TSR), multichannel FIR adaptive filters are extensively used. For the learning of such FIR adaptive filters, recursive-least-squares (RLS) algorithms are known to typically produce a faster convergence speed than stochastic gradient descent techniques, such as the basic least-mean-squares (LMS) algorithm or even the fast convergence Newton-LMS, gradient-adaptive-lattice (GAL) LMS and discrete-cosine-transform (DCT) LMS algorithms. In this presentation, multichannel RLS algorithms and multichannel fast-transversal-filter (FTF) algorithms are introduced, with the structures of some stochastic gradient descent algorithms used in ANC: the filtered-x LMS, the adjoint-LMS and the modified filtered-x LMS. The new algorithms can be used in ANC systems or for the deconvolution of sounds in TSR systems. Also, heuristic techniques are introduced, to compensate for the potential ill-conditioning of the correlation matrix in ANC or TSR systems, and for the potential numerical instability of the multichannel FTF-based algorithms. Simulations of ANC and TSR systems will compare the performance of the different multichannel LMS, RLS, and FTF-based algorithms.
Vibration analysis and design of wiper motors
Authors: Recuero Manuel , Sancho Juan , Minguez Antonio
Published: July 2002

This work has two objectives: (1) to characterize the manner of vibration of each part of a wiper motor; and (2) to find the sources of vibration so the noise emitted by the wiper motor will be known. Different measurement systems to analyze the vibrations of the wiper motor have been used. Results have been compared and the better system has been found. The results of the measurements have also been used to make some design recommendations for a new more silent wiper motor. This work started with four wiper motors. Two of them were characterized by the manufacturer of the motors as noisy and the other two as acoustically OK.
A priori assessment of the effect of small scales on sound radiation from a subsonic axisymmetric jet
Authors: Zhao Wei , Frankel Steven H. , Mongeau Luc
Published: July 2002

The effect of small scales on sound generated from a subsonic axisymmetric jet was investigated by filtering near-field data from a direct numerical simulation to determine the accuracy of the large eddy simulation technique for jet sound predictions. Lighthill’s acoustic analogy was employed to predict the far-field sound. The direct numerical simulation results were in agreement with published results [Mitchell et al., J. Fluid Mech. 383, 113–142 (1999)]. A new approach to handle the large spatial extent of the Lighthill source term yielded predictions of the far field in good agreement with the simulation results at low frequencies even for shallow angles from the jet axis. It was found that the small scales have little effect on the low-frequency sound, which is dominant in this case. The levels computed from both the filtered and unfiltered computed sound pressure field were in good agreement with those predicted by direct computations. As expected, filtering removed the small scale fluctuations in the near field, thereby reducing the magnitude of the source term for the high-frequency sound. [Work supported by NIH DCO 3577-02, RO1 grant from NIDCD.]
Nonlinear modeling of focused acoustic fields
Authors: McDonald B. Edward , Kuperman William A.
Published: July 2002

A series of simulations was performed to address the following question: If a circular piston projector were capable of producing finite amplitude beam pulses of arbitrary amplitude and bandwidth, what parameters would lead to the greatest concentration of energy within the smallest focal volume? The simulations were performed using the NPE time domain nonlinear acoustics model [B. E. McDonald and W. A. Kuperman, J. Acoust. Soc. Am. 81, 1497 (1988)] adapted to azimuthal symmetry about the beam axis [G.-P. J. Too and J. H. Ginsberg, J. Acoust. Soc. Am. 91, 59 (1992)]. For a given amplitude of the focusing wave, simulations were performed over a range of values for the parameter of nonlinearity and the effective piston aperture at the focus. Results show a strong maximum in focal gain as a function of the parameter of nonlinearity for each aperture considered. The maximum can be interpreted as competition between increasing amplitude at the piston and nonlinear defocusing as the wave propagates. Results may be rescaled to imply an optimum amplitude for a given parameter of nonlinearity. [Work supported by Saclantcen.]
Effects of small-amplitude fluctuations on thermoviscous shock wave structure
Authors: Crighton David G. , Rendon Pablo L.
Published: July 2002

We study the low-diffusivity limit of the plane Burgers equation when small-amplitude fluctuations are introduced behind the shock region. Experiments in hydraulic jump propagation suggest that these downstream fluctuations can produce large-scale effects in the shock region. A self-consistent model is proposed in which the fluctuations themselves largely determine propagation over the mean field, and are thus permitted to amplify sufficiently so as to broaden the nonuniform part of the mean flow. By means of asymptotic matching we find an expression for the power amplification of any given spectral component in a mean field where a particular gradient is sought in the shock region. Shock thickening and profile distortion are predicted for certain values of fluctuation amplitude and frequency, and these results are confirmed numerically using a pseudospectral method.
Experimental determination of acoustic bands in two-dimensional sonic band gap crystals
Authors: Sánchez-Dehesa J. , Caballero D. , Martinez-Sala R. , Rubio C. , Sánchez-Perez J. V. , Meseguer F. , Llinares J.
Published: July 2002

The dispersion relation of acoustic bands in sonic band gap crystals built up with periodic arrays of rigid cylinders in air have been characterized both experimentally and theoretically. A technique based on the analysis of the phase-shift experienced by the sound is used to construct the experimental acoustic dispersion relation. Measurements have been performed in square, triangular, and honeycomb lattices for different filling fractions. The experimental setup also allows to detect the so-called ‘‘deaf bands’’ [J. V. Sánchez-Pérez et al., Phys. Rev. Lett. 80, 3080–3083 (1998)]. A variational method is employed to calculate the corresponding acoustic bands. The good agreement between theory and experiment supports the experimental technique here described as an important characterization tool for these systems. [Work supported by CyCIT of Spain and Generalitat of Valencia.]
Stop bands of tri-dimensional sonic band gap crystals
Authors: Ribaute P. , Caballero D. , Sánchez-Dehesa J.
Published: July 2002

Acoustic and ultrasonic waves are powerful probes for many macroscopic systems ranging from the oceanic environment to devices under mechanical stress. From the technological point of view, tools must be developed in order to understand the propagation of acoustic waves through inhomogeneous media. In this work, a variational method is developed to study the acoustic response of three-dimensional systems with periodically distributed scatterers. The dispersion relations of the corresponding acoustic bands are obtained. They determine the stop bands. Also, it is shown that symmetry plays an important role in the full problem of transmitting acoustic waves through a periodic structure. If the symmetry of the external wave does not match with the band at its corresponding frequency, the acoustic energy cannot be transmitted. The existence of these bands has been previously reported in two-dimensional sonic crystals [J. V. Sánchez-Pérez et al., Phys. Rev. Lett. 80, 3080–3083 (1998)]. [Work supported by CICyT of Spain.]
Simple nondestructive quantitization of specially orthotropic materials
Authors: Preissner Curt , Royston Thomas J.
Published: July 2002

Many different plate structures can be classified as specially orthotropic, such as cross-ply composites, unidirectional composites and quarter-cut wood boards. A simple method of determining the four elastic constants of a completely free, specially orthotropic plate has been developed. An improved Rayleigh expression, utilizing beam functions, is used to represent the deflection shape of the plate. A dimensionless objective function is formed from the frequency equation. The material properties are determined by minimizing the objective function with respect to modal analysis and geometry data. The technique has been successfully used on aluminum, composite and wooden plates. The ease of the method lends itself to use in NDE of composite plates and qualification of wood used in the construction of musical instruments.
A definition of a loss factor is unique, some definitions are not
Authors: Maidanik G.
Published: July 2002

Noise control goals are often specified in terms of ratios of quadratic response quantities, among them a loss factor. Thus, the loss factor (η) is defined as the ratio of the external input power density (Πe) and the product of the stored energy density (E) and the frequency (ω), i.e., η=[Πe/(ωE)]. A unique definition of the loss factor demands that the dynamic system be enclosed so that (Πe) accounts for all the external input power density and (E) accounts for all the stored energy density generated by (Πe). Recently a number of acousticians in seeking noise control goals have defined the goals in terms of ratios that are assigned as loss factors. The definitions of these loss factors do not always conform to that uniquely defined loss factor. Those who maintain the conservative definition of a loss factor have been puzzled by reports of loss factors with values that exceed unity by several orders of magnitude. This paper attempts to examine a few examples of these less unique definitions of a loss factor and to show that a return to the unique definition is mandatory if the concept of a loss factor is not to be lost.
Measurement error compensation using integration for hidden Markov-model-based speaker recognition
Authors: Roch Marie A. , Hurtig Richard R.
Published: July 2002

Like all such measurements, the source data for speaker recognition is subject to errors in measurement due to transducer, channel, and quantization effects. When training and test equipment are known, one may calibrate the hardware and introduce a noise compensation procedure into the recognition process. In many applications, it is highly desirable for speaker recognition tasks to function with a wide variety of unknown equipment, making calibration impractical. A study is presented with the a priori assumption that for each feature vector o↘̂ observed with measurement noise, an error compensated vector o↘̂ lies within some uniformly distributed interval ±ε of the observed vector. A statistic derived from the observation set is computed and used to estimate an empirical interval in the neighborhood of each observation. An approximation to integration over the interval is carried out and is used in place of the density measurement at o↘. Tests using a 15-component cepstral feature vector derived from telephone quality speech (King corpus, San Diego speakers, sessions 1–5) have shown reductions of error rate on the order of 15% as compared to a baseline system. Techniques to reduce the algorithmic cost of the integration will also be discussed.
Flexible post-lexical processing for speech synthesis from a large unit selection database
Authors: Beutnagel Mark
Published: July 2002

Online unit selection from large speech databases provides an opportunity to essentially play back words, phrases, and even sentences which were included in a recorded corpus. This capability can be extremely useful for limited domains, e.g., application prompts. Without switching voices, such a synthesizer could integrate high-quality synthesis with near-perfect recorded material. However, traditional post-lexical processing (PLP) considers only the phoneme specifications and not the sequences which actually exist in the target database. Phonemes supplied by the dictionary are typically rewritten into a single sequence of phones with reduced vowels, flapped t’s, etc. Given the enormous variability of human speech, any single sequence is unlikely to match an entire phrase or prompt as spoken and labeled. This paper addresses the use of flexible PLP, allowing multiple transcription possibilities which are essentially equivalent, at least for the speaker in question. By building the equivalences from the specific dictionary used by the synthesizer and the detailed phonetic labeling of a specific voice database, longer regions of the database can be selected, reducing the number of concatenation points in ordinary synthesis and increasing the odds of selecting complete recorded phrases.
Matched field inversion of broadband data using the freeze bath method
Authors: Jaschke Lothar , Chapman N. Ross
Published: July 2002

This paper presents a statistical freeze bath method for geoacoustic inversion that emphasizes the search for a distribution of models that fit the data well. Contrary to simulated annealing optimization, the freeze bath samples the multidimensional model parameter space at constant freeze probability, corresponding to fixed temperatures for each parameter. The sampling process uses a heat bath algorithm as a Boltzmann sampling tool to carry out a global search over the model parameter space. The conventional heat bath algorithm is modified to sample on a fuzzy grid in order to access the entire range of parameter values. The inversion provides a set of good models that indicates how well the model parameters are constrained by the data, and reveals the degree of correlation between parameters. The efficiency of the search process is improved by reparameterizing the original model parameters to a new set based on the eigenvectors of the model covariance matrix. The inversion performance of the freeze bath is demonstrated using simulated data for a simple geoacoustic model. The method is applied to shallow water broadband data obtained during the Haro Strait geoacoustic tomography experiment to estimate a geoacoustic profile at the site.
Greenspan acoustic viscometer: Numerical calculations of fields and duct-end effects
Authors: Mehl James B.
Published: July 2002

Inertial and resistive end corrections for the Greenspan acoustic viscometer were computed using a boundary-integral-equation technique for determination of the acoustic field. Viscous effects were estimated using a boundary-layer approximation. The results apply to a circular duct coupling two concentric chambers and to ducts terminated by infinite plane baffles. The effects of rounding the sharp edge at the duct end were investigated and found to be described by simple scaling relations.
Comparison of different forms of compression using wearable digital hearing aids
Authors: Stone Michael A. , Moore Brian C. J. , Alcántara José I. , Glasberg Brian R.
Published: July 2002

Four different compression algorithms were implemented in wearable digital hearing aids: (1) The slow-acting dual-front-end automatic gain control (AGC) system [B. C. J. Moore, B. R. Glasberg, and M. A. Stone, Br. J. Audiol. 25, 171–182 (1991)], combined with appropriate frequency response equalization, with a compression threshold of 63 dB sound pressure level (SPL) and with a compression ratio of 30 (DUAL-HI); (2) The dual-front-end AGC system combined with appropriate frequency response equalization, with a compression threshold of 55 dB SPL and with a compression ratio of 3 (DUAL-LO). This was intended to give some impression of the levels of sounds in the environment; (3) Fast-acting full dynamic range compression in four channels (FULL-4). The compression was designed to minimize envelope distortion due to overshoots and undershoots; (4) A combination of (2) and (3) above, where each applied less compression than when used alone (DUAL-4). Initial fitting was partly based on the concept of giving a flat specific-loudness pattern for a 65-dB SPL speech-shaped noise input, and this was followed by fine tuning using an adaptive procedure with speech stimuli. Eight subjects with moderate to severe cochlear hearing loss were tested in a counter-balanced design. Subjects had at least 2 weeks experience with each system in everyday life before evaluation using the Abbreviated Profile of Hearing Aid Benefit (APHAB) test and measures of speech intelligibility in quiet (AB word lists at 50 and 80 dB SPL) and noise (adoptive sentence lists in speech-shaped noise, or that same noise amplitude modulated with the envelope of speech from a single talker). The APHAB scores did not indicate clear differences between the four systems. Scores for the AB words in quiet were high for all four systems at both 50 and 80 dB SPL. The speech-to-noise ratios required for 50% intelligibility were low (indicating good performance) and similar for all the systems, but there was a slight trend for better performance in modulated noise with the DUAL-4 system than with the other systems. A subsequent trial where three subjects directly compared each of the four systems in their everyday lives indicated a slight preference for the DUAL-LO system. Overall, the results suggest that it is not necessary to compress fast modulations of the input signal.
Acoustic scattering from fluid-loaded stiffened cylindrical shell: Analysis using elasticity theory
Authors: Baillard André , Conoir Jean-Marc , Décultot Dominique , Maze Gérard , Klauson Aleksander , Metsaveer Jaan
Published: July 2002

The acoustic scattering from a fluid-loaded stiffened cylindrical shell is described by using elasticity theory. The cylindrical shell is reinforced by a thin internal plate which is diametrically attached along the tube. In this model, cylindrical shell displacements and constraints expressed from elasticity theory are coupled to those of the plate at the junctions, where plate vibrations are described by using plate theory. The present model is first validated at low frequency range (k1a∼5–40) by comparison with a previous model based on the Timoshenko–Mindlin thin shell theory and by experimental results. Theoretical and experimental resonance spectra are then analyzed in a high frequency range (k1a∼120–200). Only resonances due to the S0 wave are clearly observed in this frequency range, and their modes of propagation are identified. Furthermore, A0 wave propagation is detected, because of the presence of the reflection of this wave at the shell-plate junctions.
Calculation of B/A for n-alkane liquids using the Tait equation
Authors: Hartmann Bruce , Lee Gilbert F. , Balizer Edward
Published: July 2002

The B/A parameter of acoustic nonlinearity was calculated for a series of n-alkane liquids using the Tait PVT equation of state supplemented with specific heat data. The calculations of sound speed, sound speed derivatives, the two components of B/A, and the value of B/A itself were compared with experimental data taken from the literature and with earlier calculations using a different equation of state. In addition, a comparison of the results with Ballou’s rule (linear relation of B/A and reciprocal sound speed) was made. It is concluded that B/A can be calculated from the Tait equation of state with about the same accuracy as direct measurements of sound speed versus pressure and temperature, though the the temperature derivatives of the sound speed are calculated with much lower accuracy than pressure derivatives. The calculations made using the Tait equation are about the same accuracy as calculations made using our equation of state. Also, Ballou’s rule does not hold for these liquids.
Broadband time-domain reflectometry measurement of attenuation and phase velocity in highly attenuating suspensions with application to the ultrasound contrast medium Albunex®
Authors: Hughes Michael S. , Klibanov Alexander L. , Marsh Jon N. , Miller James G. , Brandenburger Gary H.
Published: July 2002

We describe a technique for broadband measurements of the attenuation coefficient and phase velocity of highly attenuating liquid suspensions. To validate the technique we apply it to the ultrasound contrast agent Albunex® at concentrations ranging from 0.69×106 particles/mL to 364×106 particles/mL. These longitudinal wave measurements were performed on Albunex suspensions maintained at 37 °C in a special time-domain reflectometer designed and constructed in our laboratory. The frequency-dependent attenuation coefficients and phase velocities obtained in the reflectometer are compared to broadband through-transmission measurements of these same quantities, which were also performed in our laboratory. Although comparison data between the two techniques are only available at lower concentrations, the agreement is quite good and serves to validate the methods described in this paper.
A theoretical framework for granular suspensions in a steady simple shear flow
Authors: Ancey Christophe , Coussot Philippe , Evesque Pierre
Published: July 2002

We focus our attention on granular suspensions made up of noncolloidal spherical particles within a Newtonian fluid. The main objective of this paper is to provide a general framework for the formulation of the bulk stress tensor. The bulk stress within granular suspensions is mainly generated at the particle level by strong interactions between particles, such as friction, collision, and lubricated contact. The existence of a few local mechanisms is a major cause of behavior complexity at the macroscopic scale. A direct consequence is that the constitutive equation is only known for some flow conditions and given types of mixture. Here we have used a microstructural approach, which consists of considering the mixture as an effective continuum at the macroscopic level and inferring the bulk stress tensor from averaging of local interactions and local stresses. The bulk stress tensor may be split into elementary contributions pertaining to particle interactions. A complementary equation standing for the bulk energy dissipation may be needed in some circumstances. The analytical computation of these contributions is generally not possible. We present the various physical or heuristic reasonings usually proposed to circumvent this difficulty.
A retrospective multi‐center feasibility study of a new PTV margin estimation approach for moving targets using CyberKnife log files
Authors: Samadi Miandoab Payam , Saramad Shahyar , Setayeshi Saeed , Blanck Oliver
Published: April 2023

Purpose

This study investigates a new approach for estimating the planning target volume (PTV) margin for moving tumors treated with robotic stereotactic body radiotherapy (SBRT).

Methods

In this new approach, the covariance of modeling and prediction errors was estimated using error propagation and implemented in the Van Herk formula to form a Modified Van Herk formula (MVHF). To perform a retrospective multi‐center analysis, the MVHF was studied using 163 patients treated with different system versions of robotic SBRT (G3 version 6.2.3, VSI version 8.5, and VSI version 9.5) and compared with two established PTV margins estimation methods: The original Van Herk Formula (VHF) and the Uncertainty Estimation Method (UEM).

Results

Overall, the PTV margins provided by the three formalisms are similar with 4–5 mm in the lung region and 4 mm in abdomen region to the PTV margins used in clinical. Furthermore, when analyzing individual patients, a difference of up to 1 mm was found between the PTV margin estimations using MVHF and VHF. The corresponding average discrepancies for the superior‐inferior (SI) direction ranged between −0.19 mm to 0.38 mm in CK G3 version 6.2.3, −0.36 mm to 0.33 mm in CK VSI version 8.5, and −0.34 mm to 0.40 mm in CK VSI version 9.5.

Conclusions

It was found that for the lower left lung, upper left lung, lower right lung, upper right lung, central liver, and upper liver, the effect of covariance between model and prediction errors in SI direction was around 20%, 30%, 25%, 25%, 25%, and 30%, respectively. Notable covariance effects between model and prediction errors can be considered in PTV margin estimation using a modified VHF, which allowed for more precise target localization in robotic SBRT for moving tumors. Overall, in each of the three directions, the difference between MVHF and utilized clinical margins is 0.65 mm in the lung and abdominal region. Therefore, to improve the clinical PTV margins with the new approach, it is suggested to use the adaptive PTV margins in the next fractions.
Entropy‐Driven Solvation toward Low‐Temperature Sodium‐Ion Batteries with Temperature‐Adaptive Feature
Authors: Yang Chao , Liu Xiaowei , Lin Ya , Yin Luming , Lu Jun , You Ya
Published: April 2023

Salt precipitation at temperatures far above the freezing point of solvents is primarily responsible for performance decay of rechargeable batteries at low temperature, yet is still challenged by a lack of in‐depth understanding of the design principle and ultimate solutions. Here, this is resolved via tuning the entropy of solvation in a strong‐solvation (SS) and weak‐solvation (WS) solvent mixture, in which a solvation structure can spontaneously transform at low temperature to avoid salt precipitation, endowing the electrolyte with a temperature‐adaptive feature. The results affirm that such temperature‐adaptive electrolyte ensures encouraging low‐temperature performance in a hard carbon||Na2/3Ni1/4Cu1/12Mn2/3O2 full cell with 90.6% capacity retention over 400 cycles at −40 °C. The generality of the concept is further expanded to construct a series of SS–WS electrolytes as potential candidates for rechargeable low‐temperature sodium‐ion batteries. The work shed lights on the importance of entropy tuning and affords a rational viewpoint on designing low‐temperature electrolytes.
How are they doing as adults? Psychosocial and socioeconomic outcomes 11‐30 years after pediatric epilepsy surgery
Authors: Hoppe Christian , Beeres Kassandra , Witt Juri‐Alexander , Sassen Robert , Helmstaedter Christoph
Published: April 2023

Objective

Pediatric epilepsy surgery yields cure from epilepsy or complete seizure control with continued medication in many patients early in life. This study aimed to evaluate the long‐term (>10 years) psychosocial and socioeconomic outcomes of pediatric epilepsy surgery and examine the role of comorbid disability, type of surgery, seizure freedom, and age at surgery.

Methods

A novel ad hoc parent/patient questionnaire was used to assess educational and occupational attainment, marital/familial status, mobility, and other outcomes in patients who underwent unilobar or multilobar surgery for drug‐refractory epilepsy during their childhood. The questionnaire also captured information on comorbid disability.

Results

Of the 353 eligible patients, 203 could still be contacted and 101 of these (50%) returned appropriately filled‐in questionnaires (follow‐up intervals: 11‐30 [mean: 19.6] years). The cure from epilepsy rate was 53%. Type of surgery was strongly confounded by comorbid disability. Patients with comorbid disabilities had significantly lower rates of regular school degrees, gainful employment, marriage, and driving license (N = 29; 12%, 4%, 0%, 3%) compared with non‐disabled patients (N = 69; 89%, 80%, 43%, and 67%, respectively). Patients achieved lower school degrees than their siblings and parents. Non‐disabled seizure‐free patients had better employment and mobility outcomes compared with non‐seizure‐free patients. Age at surgery (<10 vs. ≥10 years of age) did not have any effect on any outcome in patients with preschool seizure onset.

Significance

Pediatric epilepsy surgery can lead to permanent relief from epilepsy in many patients, but comorbid disability strongly impacts adult life achievement. In non‐disabled patients, favorable outcomes in academic, occupational, marital, and mobility domains were achieved, approaching respective rates in the German population. Complete seizure freedom had additional positive effects on employment and mobility in this group. However, in case of chronic comorbid disability the overall life prospects may be limited despite favorable seizure outcomes.
レジオネラ肺炎を契機に発症したAcute–on–chronic liver failureの救命例(A case of acute–on–chronic liver failure caused by Legionella pneumonia)
Authors: 一樹 菅谷 , 萌 関根 , 憲哉 武藤 , 友誉 三澤 , 雅洋 岩渕 , 泰彦 塚田 , 憲 伊関
Published: April 2023

レジオネラ肺炎は，多臓器不全を合併し致死的な経過をたどることがある。今回，ACLFに伴う肝性脳症を合併するも，人工肝補助療法を導入し，救命し得た症例を経験したので報告する。症例は50歳の男性で，高度意識障害と多臓器不全のため近隣病院から転院搬送された。搬入時より意識レベルはJCS III–300であり，血液検査でアンモニアが高値であった。肝性脳症と診断し，直ちにon–line HDFによる人工肝補助療法を開始した。第2病日に尿中レジオネラ抗原が陽性となったことから，レジオネラ肺炎と診断し，それに伴って多臓器不全を発症した状態であると判断した。抗生剤については，メロペネム，レボフロキサシン，アジスロマイシンを投与した。凝固障害に対しては，適宜輸血を実施した。合計3回のon–line HDFとCHDFを交互に実施し，緩徐に意識レベルの改善が得られ，第5病日には意識清明となった。第8病日にICUを退出し，第20病日に転院した。ACLFは，最近定義された新しい疾患概念であり，代償性あるいは非代償性肝硬変に増悪因子が加わって，高度の肝機能異常を呈する病態である。治療については症候に対する対症療法が中心であり，本症例では人工肝補助療法を導入したことで覚醒が得られ，救命に寄与したと考えられた。
膵十二指腸全摘術により救命し得た急性輸入脚症候群の1症例(Acute afferent loop syndrome complicated with severe necrotizing acute pancreatitis: a case successfully salvaged by total pancreatectomy)
Authors: 岬 村崎 , 泰久 丹後 , 淳史 三中 , 弘富 張 , 尚礼 塩見
Published: April 2023

輸入脚症候群は胃切除術Billroth–IIまたはRoux–en–Y（以下R–Y）再建後の稀な合併症であるが，急性に輸入脚が完全閉塞した急性輸入脚症候群（acute afferent loop syndrome: AALS）は膵炎を併発し致死的な病態となることがある。症例は胃癌に対し幽門側胃切除，D–2郭清，R–Y再建術の既往のある81歳の男性。腹痛を主訴に当院へ救急搬送されCTで絞扼性腸閉塞と診断された。緊急手術を施行したところ，Y脚が内ヘルニアとなってclosed loop obstructionを形成しており，Y脚を引き抜き，絞扼を解除した。術後は集中治療室で全身管理を行ったが，重症急性膵炎に進展し，CTで膵周囲壊死が疑われ，膵液瘻も認めた。術後19時間後に再開腹したところ膵十二指腸壊死を疑う所見を認め，膵十二指腸全摘術（total pancreatectomy: TP）を施行した。術後より全身状態は改善し，インスリン導入，膵消化酵素補充剤を開始した。SSIを併発したが，第45病日に独歩退院した。本症例ではAALSから重症壊死性膵炎に進展したが，緊急TPにより救命し得た。十二指腸壊死を伴うAALSに対してはTPも選択肢となると考えられた。
Optimizing transition from pediatric to adult care in short bowel syndrome and intestinal failure
Authors: Kinberg Sivan , Verma Tanvi , Kaura Deeksha , Mercer David F.
Published: April 2023

As the majority of children with short bowel syndrome (SBS) and intestinal failure (IF) are now surviving into adulthood, there is a paradigm shift from short‐term management to long‐term outcomes and a growing need to focus on healthcare transition (HCT). It is imperative that adolescents and young adults with SBS and IF receive disease education, empowerment, and support as they navigate the transition from pediatric to adult care. Furthermore, both pediatric and adult healthcare providers who manage these patients should be aware of the challenges faced by this population, barriers to their HCT, and strategies to overcome them. This article reviews the literature on HCT in children with chronic illnesses, discusses barriers to HCT in SBS/IF, identifies the important constituents of the transition process in SBS/IF, and provides recommendations for the successful and smooth transition of the pediatric patient to the adult healthcare environment. Structured and multicomponent HCT programs should become the standard of care to ensure uninterrupted high‐quality care across the life span for patients with SBS/IF.
Handgrip strength is a substitutive metric to the GLIM criteria–defined malnutrition and predicts long‐term mortality among hospitalized patients with cirrhosis
Authors: Guo Gaoyue , Yang Wanting , Wang Sipu , Hui Yangyang , Cui Binxin , Wang Xiaoyu , Li Chaoqun , Mao Lihong , Fan Xiaofei , Sun Chao
Published: April 2023

Background

Hospitalized patients with cirrhosis are prone to debilitating health conditions and fluid fluctuations, posing barriers to accurately obtain anthropometric measures and physical examinations as surrogates for muscle mass within the Global Leadership Initiative on Malnutrition (GLIM). We hypothesize the handgrip strength (HGS) would serve as a substitutive metric, by comparing the diagnostic consistency and prognostic accuracy with computed tomography–demarcated skeletal muscle index (SMI)–defined malnutrition according to the GLIM criteria.

Methods

Patients with cirrhosis underwent a two‐step approach involving nutrition risk screening and those fulfilling GLIM consensus were further diagnosed. The evaluation of muscle mass as one constituent contained in the GLIM criteria was conducted by SMI and HGS, respectively. Consistency test, Kaplan‐Meier curve, and multivariate Cox regression were used to assess the performance of GLIM‐SMI and GLIM‐HGS.

Results

Among 184 hospitalized patients with cirrhosis, 63 (34.2%) and 78 (42.4%) were diagnosed with malnutrition following GLIM‐SMI and GLIM‐HGS criteria, respectively. Considering the GLIM‐SMI a gold standard, GLIM‐HGS had a sensitivity of 87.3% and a specificity of 81.0%. GLIM‐HGS criteria denoted good agreement (κ value = 0.858, P < 0.001) as compared with GLIM‐SMI. Both criteria were independently associated with 1‐year all‐cause mortality, whereas GLIM‐SMI showed slightly higher hazard ratios. Moreover, HGS positively correlated with SMI in the population alongside more pronounced correlation among patients at nutrition risk.

Conclusion

HGS may serve as a substitutive metric of muscle mass contained in the GLIM criteria to diagnose malnutrition and predict long‐term mortality among patients with cirrhosis.
The introduction of the disconnection approach into polymer synthesis
Authors: Lu Dawei , Zou Xudong , Ye Liqin
Published: April 2023

The disconnection approach, a widely utilized method of design synthesis route, has played crucial roles in contemporary organic chemistry for decades. Here, we provide an introduction to the construction of polymer main chains. The implementation of the strategy hinges on determining where to disconnect based on the successful polymerization reaction in order to infer a suitable monomer. By investigating specific covalent bonds and structures in polymers, several specific linkers are highlighted to demonstrate how to design and synthesize polymer main chains using reverse thinking, thus inspiring those in polymer synthesis.
Relativistic wormhole surrounded by dark matter halos in symmetric teleparallel gravity
Authors: Mustafa G. , Maurya S. K. , Ray Saibal
Published: April 2023

In this article we study the wormhole geometry in the galactic halo region under modified gravity, especially symmetric teleparallel gravity, where the nonmetricity scalar drives the gravitational interaction. The wormhole solutions for the assumed form have been presented, where α and β are the model parameters. The assumption of is based on the fact that its behavior should change with assumed parametric values of α as well as β within specific physical bounds. Two such models are presented based on the physically motivated shape function and energy conditions. We have elaborately shown, via mathematical calculations and graphical plots, the following features in our model: (i) energy conditions, especially NEC, which is very instructive in connection to energy violation in modified gravity theory, (ii) the wormhole solutions in the regime of Navarro‐Frenk‐White (NFW) density profiles for the galactic halo regions, (iii) treatment with particles moving in closed orbits around the wormholes which exhibit epicyclic frequencies, and (iv) the red‐blue shifts of the light coming from the wormhole throat in the vicinity of the dark matter halos. All the results and behaviors are satisfactory as well as interesting.
They Are Talking, But Is It Productive? ExploringEFLStudents' Small Group Talk
Authors: Wotring Anthony , Chen Honglin , Fraser Mark
Published: April 2023

Curricular innovations in English language programs have placed increasing emphasis on providing opportunities for students to speak in the classroom, often through communicative group activities. However, despite decades of advocacy for small group talk, a rigorous conception of the quality of talk in these groups is lacking, particularly in the ways students productively use talk to meet curriculum objectives. This paper presents an analytic framework for characterizing the productive use of small group talk, exploring data collected from English language learning students in a South Korean university. Findings demonstrate the students' talk developed in the robustness of the talk repertoires, the collaborative nature, and the connections of their talk to course outcomes. This paper closes with a discussion exploring English language students' talk, challenging current understandings of students' talk abilities by pushing beyond simple communication in a foreign language and towards productive small group talk.