bluuebunny/crossref_metadata_2025 huggingface dataset:
Loneliness and relationship dispositions in emerging adults: Gender and culture as moderators
Authors: Goh Pei Hwa , Koh Isabelle Yue Sze , Piyadigama Devmi Savidhya , Yong Khai Ming
Published: April 2023

Prior research has provided evidence of the link between loneliness and the number of past sexual partners—suggesting the role of short‐term intimate connections as a strategy to fulfill belongingness needs. The current study examined whether increased loneliness was associated with increased tendencies to engage in short‐term sexual (sociosexuality) and romantic (emophilia) relationships with a sample of 319 Malaysian emerging adults. We also tested whether these associations varied by gender and cultural orientation. Findings from a cross‐sectional survey revealed that lonelier individuals generally reported higher emophilia. The positive association between loneliness and sociosexuality, however, was only present among those who were high in vertical individualism (i.e., socialized to construe themselves as independent and different from others). Gender did not moderate either of these associations. These results suggest that the loneliness‐driven short‐term connections may be less readily manifested as sexual tendencies in populations that are more sexually conservative. Our findings highlight the importance of considering the role of cultural differences at the individual level in addition to the overall cultural context when examining intimate relationship tendencies.
Bridging multinational corporations' investment‐climate gap: Prospects for the direct claims approach
Authors: Ma Ji
Published: April 2023

Multinational corporations (MNCs) have enjoyed considerable investment rights and gained massive benefits under international investment law; at the same time, they have also significantly contributed to the climate crisis. Yet, they do not bear corresponding climate change obligations. A huge gap between MNC investment rights and climate change obligations—the MNC investment‐climate gap—persists because of MNCs' global operations, the limited reach of domestic legal mechanisms in regulating MNCs' obligations, and the ineffectiveness of international regimes at addressing MNCs' obligations. This gap is mainly due to the asymmetrical structure of the investor‐State dispute settlement regime. To correct this asymmetry, this article explores the possibility of direct claims by States against MNCs under recent investment treaties. In particular, it analyses this possibility from three angles: investor obligations, arbitral tribunals' jurisdiction and States' initiation of claims. To facilitate such claims, one must reconsider the jurisprudence of international investment law.
Lung cancer: Removing toxic dust from our environment
Authors: van Zandwijk Nico , Marshall Henry M. , Fong Kwun M.
Published: April 2023

See related article
Role of toll‐like receptors in the pathogenesis of COVID‐19: Current and future perspectives
Authors: Yang Ming‐Yan , Zheng Mei‐Hua , Meng Xiang‐Ting , Ma Le‐Wei , Liang Hai‐Yue , Fan Hua‐Ying
Published: April 2023

The coronavirus disease 2019 (COVID‐19) pandemic underlines a persistent threat of respiratory tract infectious diseases and warrants preparedness for a rapid response. At present, COVID‐19 has had a serious social impact and imposed a heavy global burden on public health. The exact pathogenesis of COVID‐19 has not been fully elucidated. Since the outbreak of COVID‐19, a renewed attention has been brought to Toll‐like receptors (TLRs). Available data and new findings have demonstrated that the interaction of human TLRs and SARS‐CoV‐2 is a vital mediator of COVID‐19 immunopathogenesis. TLRs such as TLR2, 4, 7 and 8 are potentially important in viral combat and activation of immunity in patients with COVID‐19. Therapeutics targeting TLRs are currently considered promising options against the pandemic. A number of TLR‐targeting immunotherapeutics are now being investigated in preclinical studies and different phases of clinical trials. In addition, innovative vaccines based on TLRs under development could be a promising approach for building a new generation of vaccines to solve the current challenges. In this review, we summarize recent progress in the role of TLRs in COVID‐19, focusing the new candidate drugs targeting TLRs, the current technology and potential paths forward for employing TLR agonists as vaccine adjuvants.
Validation of a single question to measure internal health locus of control in Swedish primary care
Authors: Eriksson Maria C. M. , Lindblad Ulf , Daka Bledar , Lundgren Jesper
Published: April 2023

Background

Behavioral risk factors are highlighted in the prevention of diabetes and cardiovascular disease. Screening for health locus of control could be a feasible way to better identify individuals who could benefit from preventive behavioral change interventions. The aim of the study was to investigate the correlation between a single question measuring internal health locus of control (IHLC) and the Multidimensional Health Locus of Control Scale (MHLC) and to assess how IHLC relates to the General Self‐Efficacy scale (GSE) in a primary care setting.

Methods

Primary care patients, aged 18 and older, attending three primary care centers in southwest Sweden were consecutively asked to anonymously participate in the study. The patients were given a questionnaire and instructed to return the questionnaire in a sealed box in the waiting room.

Results

In all, 519 patients were included. The correlation between MHLC Internality and IHLC was weak (r = 0.21, p < 0.001). An increase of one point on the internality scale of the MHLC gave an odds ratio of 1.19 (95% CI 1.11–1.28) for reporting high IHLC, and thus a five‐point increase gave a doubled likelihood, OR = 2.40, CI 1.67–3.46. The results for the other scales of the MHLC and GSE were similar.

Conclusion

In this study, we found weak but statistically significant support for the single‐question IHLC as a measure of internal health locus of control. Given that the correlation was weak, we recommend using the MHLC when possible.
Discovery of the novel HLA‐B*38:102 allele, a variant of HLA‐B*38:01:01, in a Russian individual
Authors: Aksenova Liliya , Ananeva Anastasiia , Andryushkina Anna V. , Shagimardanova Elena I.
Published: April 2023

One nucleotide substitution in codon 1 of HLA‐B*38:01:01:01 results in the novel allele, HLA‐B*38:102.
GRAMM: A new method for analysis of HLA in families
Authors: Ansbacher‐Feldman Zuriya , Israeli Sapir , Maiers Martin , Gragert Loren , De Santis Dianne , Israeli Moshe , Louzoun Yoram
Published: April 2023

Recently, haplo‐identical transplantation with multiple HLA mismatches has become a viable option for stem cell transplants. Haplotype sharing detection requires the imputation of donor and recipient. We show that even in high‐resolution typing when all alleles are known, there is a 15% error rate in haplotype phasing, and even more in low‐resolution typings. Similarly, in related donors, the parents' haplotypes should be imputed to determine what haplotype each child inherited. We propose graph‐based family imputation (GRAMM) to phase alleles in family pedigree HLA typing data, and in mother‐cord blood unit pairs. We show that GRAMM has practically no phasing errors when pedigree data are available. We apply GRAMM to simulations with different typing resolutions as well as paired cord‐mother typings, and show very high phasing accuracy, and improved allele imputation accuracy. We use GRAMM to detect recombination events and show that the rate of falsely detected recombination events (false‐positive rate) in simulations is very low. We then apply recombination detection to typed families to estimate the recombination rate in Israeli and Australian population datasets. The estimated recombination rate has an upper bound of 10%–20% per family (1%–4% per individual).
Effectiveness of high versus lower enteral protein intake, considering energy intake, on clinical outcomes in critically ill children: a systematic review protocol
Authors: Jotterand Chaparro Corinne , Bertoni Maluf Valeria , Moullet Clémence , Kiszio Blanche , Pugliese Marie-Thérèse , Ramelet Anne-Sylvie , Morice Claire , Valla Frédéric V. , Tume Lyvonne N.
Published: April 2023

Objective:

The objective of this review is to evaluate the effectiveness of high versus lower enteral protein intake, considering energy intake, on clinical and nutritional outcomes in critically ill children hospitalized in the pediatric intensive care unit.

Introduction:

Over and undernutrition increases the risk of morbidity and mortality in critically ill children. The impact of high versus lower enteral protein intake on clinical outcomes, considering energy intake, still needs to be investigated in children of different ages.

Inclusion criteria:

This review will consider studies of critically ill children (aged between ≥ 37 wk’ gestational age and < 18 y) admitted to the pediatric intensive care unit for a minimum of 48 hours and receiving enteral nutrition. Randomized controlled trials comparing high versus lower enteral protein intake, considering energy intake, will be eligible. Primary outcomes will include clinical and nutritional outcomes, such as length of stay in the pediatric intensive care unit and nitrogen balance.

Methods:

Using the JBI methodology for systematic reviews of effectiveness, we will search for randomized controlled trials published in English, French, Italian, Spanish, and German in electronic databases, including MEDLINE, CINAHL Complete, Embase, and the Cochrane Library, from database inception until the present. We will also search clinical trial registers and, if required, contact authors. Two independent reviewers will screen and select studies for inclusion, data extraction, and assessment of methodological quality. A third reviewer will be consulted if necessary. A statistical meta-analysis will be performed if feasible.

Systematic review registration number:

PROSPERO CRD42022315325
Digital Twin-Driven Product Sustainable Design for Low Carbon Footprint
Authors: He Bin , Mao Hangyu
Published: April 2023

Product sustainability is a pressing global issue that requires urgent improvement, and low-carbon design is a crucial approach toward achieving sustainable product development. Digital twin technology, which connects the physical and virtual worlds, has emerged as an effective tool for supporting product design and development. However, obtaining accurate product parameters remains a challenge, and traditional low-carbon product design primarily focuses on design parameters. To address these issues, this paper proposes a method for data collection throughout the product lifecycle, leveraging the Internet of Things. The paper envisions the automatic collection of product lifecycle data to enhance the accuracy of product design. Moreover, traditional low-carbon design often has a limited scope that primarily considers product structure and lifecycle stage for optimization. In contrast, combining digital twin technology with low-carbon design can effectively improve product sustainability. Therefore, this paper proposes a three-layer architecture model of product sustainability digital twin, comprising data layer, mapping layer, and application layer. This model sets the carbon footprint as the iterative optimization goal and facilitates the closed-loop sustainable design of the product. The paper envisions sustainable product design based on digital twins that can address cascading problems and achieve closed-loop sustainable design.
Unguicheylidae fam. nov., a new fossil family of prostigmatic mites (Acari: Prostigmata) from the Cretaceous Taimyr amber
Authors: Khaustov Alexander A. , Vorontsov Dmitry D. , Lindquist Evert E.
Published: April 2023

A new monotypic fossil family Unguicheylidae fam. nov. with type genus and species Unguicheylus quadriocellatus gen. nov., sp. nov. is described from the early-Cretaceous (Albian–lower Cenomanian) amber of northern Siberia (Taimyr amber, Baikura locality). The new family is provisionally placed in the superfamily Anystoidea and most similar to the family Pseudocheylidae, but differs mainly in having apomorphically adnate cheliceral bases (free, mobile bases in Pseudocheylidae), and the tarsi of all legs lacking annulated pretarsal stalks bearing reduced claws (present, apomorphic to Pseudocheylidae).
Gas-phase etching mechanism of silicon oxide by a mixture of hydrogen fluoride and ammonium fluoride: A density functional theory study
Authors: Hidayat Romel , Khumaini Khabib , Kim Hye-Lee , Chowdhury Tanzia , Mayangsari Tirta Rona , Cho Seongjae , Cho Byungchul , Park Sangjoon , Jung Jongwan , Lee Won-Jun
Published: April 2023

We report the selective etching mechanism of silicon oxide using a mixture of hydrogen fluoride (HF) and NH4F gases. A damage-free selective removal of native oxide has been used in semiconductor manufacturing by forming and removing the ammonium fluorosilicate [(NH4)2SiF6] salt layer. A downstream plasma of NF3/NH3 or a gas-phase mixture of HF and NH4F was used to form (NH4)2SiF6. We modeled and simulated the fluorination of silicon oxide and the salt formation by density functional theory calculation. First, we simulated the successive fluorination of silicon oxide using SiO2 slab models. The fluorination reactions of SiO2 surfaces by the mixture produced a volatile SiF4 molecule or a surface anion of –OSiF4−* with an NH4+ cation with low activation energies. Unlike HF, NH4F produced surface salt species consisting of a surface anion and an ammonium cation. Next, we simulated the (NH4)2SiF6 formation from the two reaction products on fluorinated SiO2 surfaces. (NH4)2SiF6 can be formed exothermally with low activation energies (0.27 or 0.30 eV). Finally, we compared silicon with SiO2 to demonstrate the inherently selective etching of silicon oxide. The fluorination reactions of silicon by the mixture showed the activation energies significantly higher than the SiO2 cases, 1.22–1.56 eV by HF and 1.94–2.46 eV by NH4F due to the less stable transition state geometries. Therefore, the selective salt formation on silicon oxide, not on silicon, is expected in near-room temperature processing, which enables selective etching of silicon oxide.
Joule heating of an emitter on the cathode surface by field electron emission current with an account of the nonisolation of the apex
Authors: Diachenko M. , Lebedynskyi S. , Kholodov R.
Published: April 2023

This work is devoted to the investigation of the nonstationary problem of the thermal conductivity of a nanoemitter on the surface of a massive copper cathode when a field electron emission current passes through it. At the same time, the dependence of volume resistivity, thermal conductivity on temperature, and size effects have been taken into account. The influence of the Nottingham effect has been considered. The dependence of the equilibrium temperature of the emitter apex on the field enhancement factor for different values of the electric field strength has been found. Based on the assumption that the initial stage of the breakdown begins when the emitter apex melts, the conditions for the occurrence of a vacuum breakdown and the influence of the Nottingham effect have been analyzed.
Color control of titanium nitride thin films
Authors: Ontoria Aian B. , Vasquez Magdaleno R.
Published: April 2023

Titanium nitride (TiN) films were deposited on 304 stainless steel substrates using a radio frequency-powered magnetron sputtering system. The influence of the argon:nitrogen gas ratio (90:10, 80:20, 70:30) and the substrate temperature (room temperature, 200 °C, 400 °C) were investigated. X-ray diffractograms revealed a crystal orientation along the (111) plane with lattice parameters ranging from 4.268 to 4.319 Å. Colorimetric analysis of the deposited films revealed a color difference (ΔEab∗) from actual gold that ranged from 2.6 to 33.2. The hardness data of the TiN-coated (ΔEab∗=2.6) revealed a 53% increase compared to the bare substrates. 300-h salt spray test showed no significant corrosion for the TiN-coated substrates. With a gold-like finish coupled with excellent mechanical properties, the TiN films can be used as a durable decorative coating for the creative industries.
Self-alignment of whole wafers using patterning for capillary forces
Authors: Walker Ernest M. , Emanuel Ako , Hallen Hans D.
Published: April 2023

Three dimensional packaging schemes take advantage of multiple substrate materials, functionality, and reduced area constraints. Alignment of stacks of wafers becomes difficult as the number increases. We investigate full-wafer self-alignment as a means for solving this problem. To date, capillary self-alignment has only been accomplished with tiny, millimeter-sale, objects. Here, wafer-level self-alignment is demonstrated with capillary alignment forces, and we describe several needed, nontrivial advances and considerations compared to the chip alignment. The patterning scheme and the alignment force character are found to be crucial to ensure alignment at the wafer scale. Avoidance of alignment at local minima with the use of multiple length scales, prevention of upper wafer dragging by balancing the wafer and using engineered flow channels, and increased pattern features at small misalignments to combat the decreased alignment force are all discussed. A capture range of a few millimeters in position and several degrees in rotation for the self-alignment is achieved by patterning a hydrophobic self-assembled monolayer. These advances for large structure self-alignment offer a path forward for self-assembly of wafer stacks or other complex, large structures useful for mmWave, 5G antennas, for example. The scheme is compatible with a bonding scheme using the bonding precursor as the alignment fluid.
Reduced order modelling using parameterized non-uniform boundary conditions in room acoustic simulations
Authors: Llopis Hermes Sampedro , Jeong Cheol-Ho , Engsig-Karup Allan P.
Published: April 2023

Quick simulations for iterative evaluations of multi-design variables and boundary conditions are essential to find the optimal acoustic conditions in building design. We propose to use the reduced basis method (RBM) for realistic room acoustic scenarios where the surfaces have inhomogeneous acoustic properties, which enables quick evaluations of changing absorption materials for different surfaces in room acoustic simulations. The RBM has shown its benefit to speed up room acoustic simulations by 3 orders of magnitude for uniform boundary conditions. This study investigates the RBM with two main focuses: (1) various source positions in diverse geometries, e.g., square, rectangular, L-shaped, and disproportionate room, (2) two-dimensional and three-dimensional (3D) inhomogeneous surface absorption by parameterizing numerous acoustic parameters of surfaces, e.g., the thickness of a porous material, cavity depth, switching between a frequency independent (e.g., hard surface) and frequency dependent boundary condition. Results of numerical experiments show speedups of more than 2 orders of magnitude compared to a high fidelity numerical solver in a 3D case where reverberation time varies within one just noticeable difference in all the frequency octave bands.
The effects of broadband elicitor duration on a psychoacoustic measure of cochlear gain reduction
Authors: Salloom William B. , Bharadwaj Hari , Strickland Elizabeth A.
Published: April 2023

Physiological and psychoacoustic studies of the medial olivocochlear reflex (MOCR) in humans have often relied on long duration elicitors (>100 ms). This is largely due to previous research using otoacoustic emissions (OAEs) that found multiple MOCR time constants, including time constants in the 100s of milliseconds, when elicited by broadband noise. However, the effect of the duration of a broadband noise elicitor on similar psychoacoustic tasks is currently unknown. The current study measured the effects of ipsilateral broadband noise elicitor duration on psychoacoustic gain reduction estimated from a forward-masking paradigm. Analysis showed that both masker type and elicitor duration were significant main effects, but no interaction was found. Gain reduction time constants were ∼46 ms for the masker present condition and ∼78 ms for the masker absent condition (ranging from ∼29 to 172 ms), both similar to the fast time constants reported in the OAE literature (70–100 ms). Maximum gain reduction was seen for elicitor durations of ∼200 ms. This is longer than the 50-ms duration which was found to produce maximum gain reduction with a tonal on-frequency elicitor. Future studies of gain reduction may use 150–200 ms broadband elicitors to maximally or near-maximally stimulate the MOCR.
Assessing the acoustic impedance of indoor wall surfaces through a phase array sensor
Authors: Yilmazer Cengiz , Yilmazer Semiha , Fasllija Ela
Published: April 2023

Reliable data on the acoustic absorption behavior of building materials are crucial for predicting and, therefore, designing desired acoustic conditions in the built environment. The existing methods, such as impedance tube and reverberation room, might not always be feasible due to their ownrespective limitations such as angle of incidence, large materials samples, and reproducibility issues. In this light, this study is concerned with incorporating a method based on a phased array sensor to predict the random acoustic impedances of an indoor wall surface. Considering multipath propagation in a reverberant field, it focuses on accurately designing the array shape and the sensor number. As a case study for validation, it uses parallel arranged micro-perforated panels (MPP) placed as a wall finishing material in a 10.2m × 5.47m × 3.6m sized room. Comparisons between theoretical and predicted results through the implemented method show a fair agreement. The material was also previously assessed in the impedance tube for its normal absorption coefficient. Further comparisons between results obtained through geometrical acoustics software and impedance tube are also discussed for their discrepancies regarding the proposed method.
Comparing acoustical worship ambience of churches built by Spanish Franciscans: Nossa Senhora do Pilar (Goa) and Mission Concepcion (Texas)
Authors: Tavares Menino A. , Wiseman Susan
Published: April 2023

Spanish Franciscan Friars established "Nossa Senhora do Pilar” church at Pilar (Goa) in 1613 and "Mission Concepción” at San Antonio (Texas) in 1711. This cross-cultural comparative acoustical study of these churches connects sound decay measures (ISO 3382) with auditory, affective, and meta-physical perceptions (complementing ISO/TS 12913-1/2/3). At p ≤ 0.05, "Mission Concepcion” was found more reverberant than "Pilar"; "sacred music from the choir-loft” of "Mission Concepcion” was perceived "louder” and "clearer” than from the nave floor; whereas, in "Pilar,” "sacred music from the nave floor” was perceived "louder” than from the choir-loft; perception of "pleasantness” and "eventfulness” in both churches showed no significant difference for sacred music from either source; "sacred music from the choir-loft” of "Mission Concepcion” evoked better perception of "heightened awareness,” "stillness,” and "inspiration"; perceived "loudness” of "sacred music from the choir loft” in "Pilar" showed positive correlation with RT60, D50, TS, and STI and negative correlation with C80; perception of "inspiration” by "sacred music from the choir loft” in "Pilar” was positively correlating with RT60, TS, and STI and negatively correlating with C80 and D50. This study identified character defining acoustical differences between "Pilar” and "Mission Concepcion” which accentuate each of this historic church as a "unique living heritage."
Clinical experience with a commercial histotripsy system for the ablation of liver tumors
Authors: Ahmed Osman , Bader Kenneth B.
Published: April 2023

Liver cancer is a major burden on the American public, with an estimated 30k new diagnoses in 2022. The limitations of current treatment options motivate alternative approaches to improve patient outcomes. Histotripsy is a focused ultrasound therapy that ablates tissue with bubble cloud activity. The capacity of this technology to address liver lesions is currently under investigation (clinicaltrials.gov identifier NCT04572633). In this talk, we will review recent clinical experience with a commercial histotripsy system (HistoSonics, Inc., Ann Arbor, MI) for one site in this trial. Patients with hepatocellular carcinoma or liver metastases admitted to the University of Chicago Medical Center were screened for inclusion criteria, including lesion size (<3 cm diameter) and depth (<1 cm from liver capsule), the availability of acoustic window, among other specifications. To date, one procedure was performed, with a second scheduled. Identifying the lesion was the most challenging aspect of the procedure, in part due to differences in the window of the ultrasound imaging used for in situ guidance and pre-treatment diagnostic imaging with MRI. Post treatment imaging confirmed ablation of the targeted region, demonstrating technical success. Early experience indicate histotripsy is a strong candidate as the modality of choice for liver lesions.
Heterogenous angular spectrum approach based holograms for trans-skull focused ultrasound therapy
Authors: Dash Pradosh Pritam , Arvanitis Costas
Published: April 2023

Focused Ultrasound (FUS) therapy in the brain entails accounting for strong distortions in the transmitted wavefields introduced by the skull. While these aberrations are compensated by MR-guided FUS (MRgFUS) phased array-based systems by adjusting the phase and amplitude of individual transducer elements, their cost and reliance on MRI may limit their widespread adoption. This work presents phase-only acoustic holograms coupled to a single transducer element as a safe, effective, and affordable alternative. We used the Heterogenous Angular Spectrum Approach (HASA) to propagate between the transducer and target plane(s) and applied automated differentiation for gradient computation to iteratively optimize the phase of the holographic lens. To test our design approach, we employed experimentally validated k-wave simulation. Our results show a 9 dB increase in the peak signal-to-noise ratio (PSNR) of the target acoustic field at 1 MHz as compared to the case where aberrations are uncorrected. Furthermore, we addressed the effect of frequency and aperture on the quality of hologram construction. We showed the feasibility of implementing it in a clinical-scale FUS system targeting deep (>6 cm) brain structures. In summary, the combination of HASA with automated differentiation is an efficient and accurate tool for hologram design through heterogeneous media.
Real-time processing approaches for interactive room acoustic auralization in the rtSOFE
Authors: Seeber Bernhard U.
Published: April 2023

Room acoustic simulation of early reflections with the mirror-image method for arbitrary room geometries is an exponential problem, which, if computed to a high reflection order, will quickly exceed available computational and memory resources. The real-time Simulated Open Field Environment (rtSOFE) is freely available room-acoustic simulation and auralization software based on the mirror-image method. For auralization, rtSOFE synthesizes room impulse responses for each playback channel from the list of mirror images. A convolver program receives these seconds-long room impulse responses and convolves them for each sound source, sums across sources, and performs the playback equalization. Both programs perform computations in multiple threads in parallel using the OpenMP library. Many operations are implemented with Intel Advanced Vector Extensions (AVX) to increase processing speed. Image source trees are terminated after a definable number of invisible parent sources, keeping the number of computed mirrors manageable. With this, rtSOFE is capable of computing room impulse responses to high reflection orders in interactive real-time settings. I will present the software concept and discuss the approaches that speed up the computation.
Interpolation of scheduled simulation results for real-time auralization
Authors: Schäfer Philipp , Garrett Fatela João , Vorlaender Michael
Published: April 2023

The approach of auralization allows rendering plausible audio signals based on purely synthesized data. One key aspect for this is the simulation of sound propagation. Using sophisticated physics-based models, even complex situations—like sound propagation through an inhomogeneous, moving atmosphere—can be considered. However, even with fast approaches based on geometrical acoustics such simulations might not be real-time capable when being integrated in the auralization processing chain. This is because the update rate of the simulations is significantly lower than the audio block rate which can lead to artifacts, especially when considering effects like the Doppler shift. In this contribution, we propose a method aiming to run an artifact-free auralization despite a relatively low and potentially irregular simulation update rate. For this purpose, the simulations are run in a thread separate from the main processing chain and the respective outputs are interpolated. The method is applied to an aircraft flyover scenario considering curved sound propagation in a stratified, moving atmosphere.
The six prototype microphone elements that led to the Shure Unidyne I Model 55
Authors: Pettersen Michael S.
Published: April 2023

Benjamin B. Bauer (1913–1979) was an ASA Fellow and awarded the ASA Silver Medal (1978). He held over 100 patents for acoustical/audio technology, with his 1941 patent being arguably the most significant: the Uniphase Acoustical Network principle, integral to the Shure Unidyne model 55 microphone. Introduced in 1939 and still manufactured today, the Shure Unidyne was the first moving coil unidirectional microphone using a single dynamic element. Six prototype mic elements for the Unidyne, fabricated by Bauer in the late 1930s, reside in the Shure archive. This presentation provides details on each prototype using photos, drawings, and Bauer’s text from his lab notebooks, providing insight into the creation of the one of the world’s most famous microphones.
Trends in the development of measurement microphones
Authors: Rasmussen Per
Published: April 2023

Measurement microphones are, in principle, simple transducers that convert dynamic pressure fluctuations into an electrical output signal. The range of applications is, however, extremely wide—from measuring exceptionally low-level signals (below 0 dB; for example, measuring tiny insects) to the 190 dB signal of large rocket launches. The frequency range of interest spans from below 0.1 Hz for sonic boom measurements to 200 kHz or more for detailed investigations of very short impulses or wind tunnel scale modelling. At the same time, the individual application may mandate specific mounting conditions with specialized form factors for the microphone and associated preamplifier design. This trend towards application-specific testing has led to the development of a wide range of specialized microphones and accessories. Still, this wide variety of measurement microphones must measure accurately and be calibrated to be traceable to the basic unit of measure as, for example, defined by the SI system. This is ensured by maintaining reference to the basic IEC definition of measurement microphones in the IEC 61094 series of standards for microphones and calibration methods.
Non-equilibrium strain and elastic hysteresis in consolidated granular media
Authors: Scalerandi Marco , Kober Jan , Zeman Radovan
Published: April 2023

The physical origin of hysteretic elasticity in consolidated granular media is still debated. The hypothesis of non-equilibrium strain slowly relaxing towards an equilibrium residual strain, dependent on the amplitude of the applied strain, is a possible candidate for the explanation of slow dynamics (conditioning and relaxation) observed in rocks, concrete and other granular media. Starting from relaxation experiments, i.e., the slow recovery of the modulus/velocity to its linear value after the sample has been externally perturbed, we introduce here an analytical expression for the temporal evolution towards equilibrium. The corresponding differential equation is then used to separate hysteresis from classical nonlinearity in both Static and Dynamic Acoustoelastic experiments. The simple theory proposed allows to explain most of the experimental results for sandstones: generation of butterfly loops (hysteresis) in the dependence of velocity on strain, anisotropy effects on shear wave velocities and presence of slow dynamic effects during creep in static testing.
Temporal pitch processing in an animal model of normal and electrical hearing
Authors: Middlebrooks John C. , Richardson Matthew L. , Lin Harrison W. , Carlyon Robert P.
Published: April 2023

Cochlear-implant users typically exhibit only limited sensitivity to temporal fine structure (TFS). We are developing a cat animal model in which to explore alternative modes of electrical stimulation that might improve TFS sensitivity. Normal-hearing cats were trained to detect changes in rates of acoustical pulse trains. The pulses were non-resolved harmonic complexes that were band-limited to stimulate the basal cochlear turn, which is the location that is accessible to feline cochlear implants. The rate sensitivity of that temporal pitch was like that of human listeners but shifted upward in rate by ∼1 octave. Scalp recordings from sedated cats showed a frequency following response (FFR) across all tested rates, up to 600 pulses per second. Changes in pulse rates elicited an Acoustic Change Complex (ACC) that showed a rate sensitivity parallel to that of perception. That suggests that the ACC can be used as a surrogate for psychophysical performance. Cats that were implanted chronically with conventional intra-scalar cochlear implants exhibited electrically-evoked FFR and ACC that showed rate sensitivity largely similar to that in normal-hearing cats. These results validate the cat animal model for ongoing studies of transmission of TFS with electrical cochlear stimulation. [Work supported by the NIDCD and the Wellcome Trust]
Self-adapting band gaps in rotating elastic metamaterials
Authors: Matlack Kathryn , Arretche Ignacio
Published: April 2023

Rotation in mechanical systems can drastically change their vibrational response. For example, it can enable new properties, such as break time-reversal symmetry and induce non-reciprocity in acoustic metamaterials, due to Coriolis forces and gyroscopic effects. Rotation can also be highly detrimental: for example, synchronous vibrations occur in rotating mechanical components and can be extremely damaging when they coincide with system resonances. In addition, centrifugal forces from rotation significantly affect the dynamics of rotating systems, through stress stiffening and spin softening, however their effects on acoustic and elastic metamaterials have rarely been explored. Here, we demonstrate that centrifugal forces in rotating elastic metamaterials enable band gaps that “self-adapt” to synchronous vibrations, attenuating these vibrations over a broadband frequency range. Specifically, this talk presents a reduced order model that captures stress stiffening effects on the band gaps of a rotating elastic metamaterial. The resonators are beams with tip masses oriented perpendicular to the rotational axis, such that stress stiffening causes their resonant frequency to be linearly proportional to the rotational speed. The reduced order models are validated by full finite element simulations of a 3D elastic metamaterial whose band gap self-adapts to synchronous vibrations that are linearly proportional to rotational speed.
Achieving any desirable dispersion curves using non-local phononic crystals
Authors: Kazemi Arash , Deshmukh Kshiteej , Chen Fei , Liu Yunya , Deng Bolei , Zhu Xuan , Fu Henry , Wang Pai
Published: April 2023

Phononic crystals and vibro-elastic metamaterials are characterized by their dispersion relations—how frequency changes with wave number/vector. While there are many existing methods to solve the forward problem of obtaining the dispersion relation from any arbitrarily given design. The inverse problem of obtaining a design for any arbitrarily given dispersion bands has only had very limited success so far. Here, we report a new design scheme for arbitrary dispersion relations by incorporating non-local interactions between unit cells. Considering discrete models of one-dimensional mass-spring chains, we investigate the effects of both local (i.e., springs between the nearest neighbors) and non-local (i.e., springs between the next nearest neighbors and other longer-range springs) interactions. First, we derive the general governing equations of non-local phononic chains. Next, we examine all design constraints for a linear, periodic, passive, statically stable, non-gyroscopic, and free-standing system. Finally, we perform analytical calculations and numerical simulations to solve the inverse problem. The results illuminate a new path toward novel wave manipulation functionalities, such as ordinary and higher-order critical points with zero-group-velocity (ZGV) modes, as well as multi-wavelength and multi-speed propagations of the same mode at the same frequency.
Surface wave suppression in granular media using a partially embedded meta-barrier
Authors: Pillarisetti Lalith Sai Srinivas , Lissenden Cliff , Shokouhi Parisa
Published: April 2023

Existing studies on meta-barrier designs for suppressing surface modes in inhomogeneous granular media are limited to meta-barriers comprising vertical or horizontal oscillators. However, a clear understanding of the surface mode hybridizations with the local resonances of the resonators is lacking and could help realize more realistic meta-barrier designs for surface wave control in granular media. In this work, we propose a meta-barrier comprising partially embedded rod-like resonators to study the hybridization of the fundamental surface modes: PSV1 and PSV2, with the longitudinal and flexural resonances of the resonators that enable surface mode suppression. The hybridized dispersion curves and frequency-domain finite element simulations with the meta-barrier demonstrate preferential hybridization of the PSV1 mode with the longitudinal resonance of the resonators, enabling PSV1 mode suppression above the hybridized longitudinal-resonance mode cut-off frequency. Unlike the PSV1 mode, PSV2 hybridizes with both longitudinal and flexural resonances, making it challenging to suppress the mode. However, we observe that enhancing the filling fraction of the meta-barrier promotes PSV2 mode suppression as the flexural-resonance hybridized modes are localized under the meta-barrier. The time-domain finite element simulation using a broadband excitation source further numerically validates the meta-barrier design for applications in vibration mitigation and seismic isolation of structures.
Multiple scattering model for collections of bianisotropic acoustic scatterers
Authors: Lawrence A. J. , Wallen Samuel P. , Haberman Michael R.
Published: April 2023

The magnitude of an acoustic point source is traditionally described as monopole, dipole, or higher-order multipole source strengths. The polarizability tensor, commonly used in electromagnetics, can be used to describe the scattering from an acoustically small heterogeneity in a background medium as monopole, dipole, and higher order multipoles due to the pressure and particle velocity at the scattering site. Recent research on bianisotropic acoustic (or Willis) metamaterials has employed the acoustic polarizability tensor as a convenient descriptor of the scattered fields from scatterers with asymmetries since non-zero off-diagonal terms indicate the existence and relative strength of Willis coupling. In the present work, we employ the polarizability tensor in a multiple scattering formulation for N arbitrary, point scatterers. The polarizability tensor for an example scatterer is extracted from finite element simulations by generalizing the approach of Su and Norris [Phys. Rev. B 98, 174305, (2018)]. We then provide a metasurface example to demonstrate the ability of the multiple scattering approach to consider variability in scatterer position and orientation in the calculation of the total scattered field.
Survey of the classroom acoustics in Utah elementary and secondary schools and voice amplification systems
Authors: Robertson Megan R. , Anderson Brian E.
Published: April 2023

Poor acoustics in a classroom can lead to vocal strain and heath challenges for teachers using these rooms over many years. In some cases, voice amplification can be used to help alleviate vocal strain. The acoustics of various types of elementary and secondary school (K–12) classrooms in Utah were assessed with speech parameters calculated from impulse response measurements for teacher to student interactions (using a dodecahedron loudspeaker and microphone) as well as oral binaural impulse responses for the teacher’s perception of the room (using a KEMAR mannequin with a mouth simulator). The use of and impact on speech intelligibility of voice amplification was also investigated. This study is part of an overall effort to better assess the degree to which rooms with poor acoustics may impact vocal strain.
Paying attention to the man behind the curtain: Jim Simmons' contributions to bat echolocation
Authors: Warnecke Michaela
Published: April 2023

Echolocating big brown bats (Eptesicus fuscus) perceive their surroundings by broadcasting frequency-modulated (FM) ultrasonic pulses and processing returning echoes. These bats commonly navigate acoustically-cluttered environments, in which each broadcast is followed by multiple echoes at varying time delays and echo amplitudes. The bat must decode these echo cascades in order to create a coherent percept of its surroundings and adapt its flight and echolocation behavior in real time. Jim Simmons’ physiological and behavioral work—which continues to fuel research questions to this day—has significantly helped our understanding of how this decoding might be possible. In this talk, I will revisit some of Jim Simmons’ seminal work that contributed to our understanding of echolocation processing, and describe its influence on new generations of researchers who continue to build on Jim’s important work.
The soundscape of dense bat swarms: Differences based on location within the group
Authors: Eveland Keegan , Stevenson Robert , Domski Paul , Kloepper Laura
Published: April 2023

The laboratory work of Jim Simmons and colleagues has provided key information on how bats use harmonic structure to identify targets from background clutter. Although advantageous for detecting targets straight ahead, the question remains as to how bats modify echolocation, if at all, when identification of objects in the periphery may be needed, such as when flying in a dense group. Based on the work of Dr. Simmons and colleagues, we predicted that free-tailed bats in central positions of swarms may use different echolocation signals than bats on the periphery. We investigated this by quantifying the soundscape based on location within the group. To overcome the challenge of recording inside a dense swarm, we developed a microphone/camera unit carried by a trained Harris hawk that flew through the bat swarm. Frequency spectra were extracted and analyzed based on the frequency-dependent amplitude compared to position in the swarm. We found a significant difference in the soundscape between the ‘Edge’ and ‘Middle’ of the swarm for frequencies above 40 kHz, suggesting bats in central positions of the swarm produce echolocation signals with more energy in higher frequencies, which may aid in distinguishing their calls from conspecifics.
Open ocean ambient noise data in the frequency band of 100 Hz–50 kHz from the Pacific Ocean: A legacy of Jeffrey A. Nystuen
Authors: Yang Jie , Riser Stephen , Thorsos Eric I.
Published: April 2023

Ocean ambient noise, spanning from a few hertz to tens of kilohertz, is often the limiting factor for sonar performance in target detection, location, and identification. In this frequency band, wind generated surface breaking waves produce bubbles near the surface that are the dominant ambient noise source. In this work, results from a long-term collaboration between NOAA/ NASA and ambient noise study pioneer, Jeffrey A. Nystuen, are presented. Specifically, two-decades of ambient noise data from six deep ocean moorings with companion surface meteorological measurements are used to validate ambient noise models. Excluding data during rainy periods, the ambient noise level is investigated under different wind speed ranges. For wind speeds exceeding 15 m/s, the ambient noise level displays a sharp drop-off and creates a “cross-over” as the spectral level at higher wind speeds and frequencies becomes lower than that at lower wind speeds. Data-model comparisons show a mismatch, as existing models are monotonic in nature, i.e., the modeled spectral level increases with increasing wind speed for all frequencies. This mismatch, currently under investigation, is likely due to attenuation when ambient sound propagates through the deeper and denser bubble layer under high sea conditions. [Work supported by NOAA, NASA, and ONR.]
Variability analysis of low-frequency and very low-frequency ambient ocean noise
Authors: Bradley David L. , Eller Anthony
Published: April 2023

Much of the information presented was made possible by the presence over the past several years of a collection of deep water hydroacoustic arrays with long-term, high data rate recorders of ocean ambient noise, deployed and maintained under the auspices of the United Nations Comprehensive Nuclear Test Ban Treaty Office (CTBTO). Not only does the long time span of the noise record allow high frequency resolution of annual and multi-year variability, but the high data rate supports as well the analysis of high temporal resolution minute-by-minute variability. The present analysis is directed at acoustic frequencies where the noise level and its variability are governed primarily by natural events : planetary—such as the influence of tides, oceanographic—such as the influence of El Nino, and meteorological—such as the influence of storms and routine weather. The analysis is focused on the fluctuations of a series of narrow band tonals at acoustic frequencies between 0.1 and 10 Hz. Results of the analysis display the time scales of the various processes that drive the fluctuations.
Source separation and arrival angle estimation using a single acoustic vector sensor
Authors: Laferriere Alison B. , Thode Aaron M.
Published: April 2023

Extracting individual time signatures from two angularly-separated sources overlapping in time and bandwidth typically requires coherent array processing on multiple hydrophones, a process whose performance is degraded by limited aperture and spatial aliasing. Vector sensors, which measure both acoustic pressure and particle velocity, can measure an acoustic field’s directionality in a single, compact sensor package. Standard beamforming techniques can be applied to the outputs of a vector sensor to suppress one source’s signal, but its efficacy is limited by the angular insensitivity of the resulting cardioid beam pattern. Here we use fundamental physical principles to demonstrate that measurements on a 2-D vector sensor can completely determine the azimuths, amplitudes, and relative phases of two horizontal plane waves of the same frequency, achieving source separation and direction-of-arrival estimates for both. Interference between the waves creates a reactive intensity whose orientation is perpendicular to the bisector of the two wavenumber vectors. This observation leads to closed-form inversion formulas. Data examples of the technique are illustrated using overlapping humpback whale songs off Hawaii, and on weak airgun and bowhead whale signals embedded within intense directional noise from a nearby drilling site in the Beaufort Sea. [Work sponsored by ONR TFO.]