Article
Geochemistry & Geophysics
Igor Ravve, Zvi Koren
Summary: The study presents an effective method for solving the inverse problem of finding the slowness vector in anisotropic elastic media by introducing geometric constraints and polynomial equations, particularly useful for solving two-point ray bending problems. This method provides physical solutions in polar anisotropic media and combines the resolving equations into a single univariate sixth-degree equation, offering slowness solutions for qP and qSV waves, reducing computational complexity.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Acoustics
Dominik Scholl, Florian Ebert, Philip Leistner
Summary: The study investigated the influence of flow on the transmission loss of duct bends, with results showing that mean flow velocities up to 40 m/s have mostly negligible impact, but flow direction plays a significant role in higher order modes propagation where there are significant differences between upstream and downstream transmission loss. Inter-modal acoustic scattering and mode transformation in the flow constriction zone have been identified as the reasons for these differences.
Article
Multidisciplinary Sciences
Mingduo Zhao, Anders Fridberger, Stefan Stenfelt
Summary: The study investigated the influence of vibration direction on bone conduction hearing by providing BC stimulation in five different directions at the vertex of the guinea pig skull. The study found that at lower frequencies, the vibration direction between the right and left side contributed most to BC hearing in guinea pigs, while at higher frequencies, the anteroposterior direction of the head had the greatest impact.
SCIENTIFIC REPORTS
(2021)
Article
Acoustics
Riccardo Marrocchio, Angelis Karlos, Stephen Elliott
Summary: A WKB solution to the cochlear wave equation was derived, showing that the nondimensional damping parameter and phase-shift parameter have the greatest influence on the response under normal conditions in the cochlea. In the case of an acoustic rainbow sensor, the nondimensional compressibility parameter plays a more dominant role in determining the response, which is governed by the ratio of the Helmholtz resonator volume to that of the connecting duct.
Article
Acoustics
Ales Vetesnik, Vaclav Vencovsky, Anthony W. Gummer
Summary: This study presents a solution for distortion products in a two-dimensional nonlinear cochlear model and identifies a long-latency component of distortion-product otoacoustic emissions caused by perturbation of nonlinear force.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Optics
J. A. Reboucas, P. A. Brandao
Summary: This paper applies perturbation theory to investigate one-dimensional scattering systems composed of inhomogeneous and isotropic slabs. The transmitted and reflected amplitudes are expressed as Born series and approximate solutions are obtained using Pade approximants with high and arbitrary accuracy. The approach is versatile and can handle oblique incidence.
Article
Geochemistry & Geophysics
Peter Moczo, Jozef Kristek, Miriam Kristekova, Jaroslav Valovcan, Martin Galis, David Gregor
Summary: By analyzing equations of motion and constitutive relations, we gain insight into the accuracy of finite-difference schemes. We present heterogeneous formulations for four wavefield configurations in an elastic isotropic medium. Fourier transformation to the wavenumber domain and inverse Fourier transform to the space domain allow for analysis of spatial discretization and wavenumber band limitation. The implications of heterogeneous medium and Nyquist-wavenumber band limitation have important implications for FD modeling.
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2023)
Article
Chemistry, Physical
Sansit Patnaik, Mehdi Jokar, Wei Ding, Fabio Semperlotti
Summary: This study explores the role of microstructure in determining the macroscopic static response of porous elastic continua and exposes the presence of position-dependent nonlocal effects that are strictly correlated to the configuration of the microstructure. A nonlocal continuum theory based on variable-order fractional calculus is developed to accurately capture the complex spatially distributed nonlocal response. The potential of the fractional approach is demonstrated by simulating the nonlinear thermoelastic response of porous beams, and its performance is compared with high-fidelity finite element models that fully resolve the pores' geometry.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Xiaoxuan Tan, Kaijie Wu, Shuang Liu, Yifang Yuan, Chao Chang, Wei Xiong
Summary: This study introduces a minimally invasive technology called terahertz wave modulation that can enhance hearing perception in animals. By modulating the currents in cochlear hair cells, this technique can reversibly increase mechano-electrical transducer currents and voltage-gated K+ currents, resulting in improved hearing sensitivity.
Article
Materials Science, Multidisciplinary
Hiroki Arisawa, Shunsuke Daimon, Yasuyuki Oikawa, Takashi Kikkawa, Eiji Saitoh
Summary: The spatial dependence of magnetization dynamics in a Y3Fe5O12 film under a magnetic-field gradient is investigated using local spin pumping and inverse spin-Hall effects. The results show that when microwaves are irradiated locally, magnetization precession is excited at a distant position from the irradiation location. By analyzing the field and microwave frequency dependence, it is found that the observed magnetization dynamics are due to nonlocal resonance of magnetization and spatial changes in spin-wave dispersion under the magnetic-field gradient, suggesting the potential to realize a microwave spectrometer known as a spin-wave cochlea.
Article
Optics
Shuqi Mu, Yingtong Shi, Yintong Song, Wei Liu, Wanxue Wei, Qihuang Gong, Dashan Dong, Kebin Shi
Summary: Analytical modeling of optical field propagation in a scattering medium is important for computational optics. However, there lacks an analytical model to include the full tensor nature of birefringent scattering. In this study, we present an analytical tool with a polarization transfer function tensor to model the field propagation in a birefringent scattering medium. The proposed model provides a more accurate and efficient forward analytical tool for iterative reconstruction of birefringence-related scattering processes.
Article
Multidisciplinary Sciences
Kosisochukwu P. Nnoli, Stefan Kettemann
Summary: The study systematically investigates the impact of reduced grid inertia, due to increased renewable energy resources, on the propagation of disturbances in power grids using DigSILENT PowerFactory software. The results show a linear relationship between time of arrival of disturbances and geodesic distance, as well as the importance of network topology quantified by the meshedness coefficient. Additionally, introducing an effective distance concept based on local inertia distribution provides a better understanding of disturbance propagation dynamics.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Mechanical
Mingqing Du, Xuming Liu, Yao Wang, Hanxuan Huang, Zhen Zhu, Yongjun Zhang, Xuchun Wang
Summary: In this study, the crack propagation behaviors in an inverted arch during floor heave were investigated. The effects of the thickness and curvature of the inverted arch on crack propagation were analyzed. The study revealed that tensile cracks first form at the center of the arch, which then ruptures the arch in longitudinal and vertical directions. The results of the study can inform the optimization and design of inverted arch structures.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Environmental
Hadi Mashhadban, Asskar Janalizadeh Choobbasti, Issa Shooshpasha, Mehdi Ashtiani
Summary: The presence of horseshoe tunnels has a significant effect on the seismic response of slopes, increasing the amplitude of seismic response by approximately 30% and 70% for the upstream and inclined surfaces of the slope, respectively.
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2021)
Article
Materials Science, Multidisciplinary
Wen-Yu Shan
Summary: In this study, the magnetization-induced circular phonon dichroism in transition metal dichalcogenides is investigated. It is found that, instead of the conventional deformation potential coupling, pseudogauge-type electron-phonon coupling plays a crucial role in the emergence of this phenomenon. By varying the gate voltage, a tunable circular phonon dichroism can be achieved, paving the way for various physics and applications of two-dimensional acoustoelectronics.