Article
Physics, Particles & Fields
Igor Pesando
Summary: We discuss the failure of perturbative particle paradigm in certain backgrounds with space-like singularity but asymptotically flat, and argue for the existence of non-perturbative evolution operator. Furthermore, the complete breakdown of perturbative expansion in the covariant formalism in string theory is explained at least at the tree level.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Multidisciplinary Sciences
Lin Liu, Xiumei Zhang, Xiuming Wang, Xiao He, Hao Chen
Summary: The knowledge of acoustic wave propagation in a borehole embedded in gas hydrate-bearing sediments is essential for the exploitation of gas hydrate. This study introduces a real-axis integration method to calculate the borehole acoustic field in a three-phase porous medium based on the Biot-type three-phase theory. A component wave approach, combined with the branch-cut integral method and the residue theorem, is proposed to study the borehole wave propagation in a three-phase porous medium. The results provide a theoretical basis for the subsequent inversion of reservoir parameters.
SCIENTIFIC REPORTS
(2023)
Article
Mathematics, Applied
Sandhyarani Bandari, Malla Reddy Perati
Summary: This paper investigates the radial vibrations of a fluid-filled poroelastic cylindrical bore saturated with two immiscible fluids of infinite extent. The frequency equation is obtained by considering the stress-free boundaries. The importance of wave propagation in a fluid-filled borehole embedded in an infinite poroelastic medium is discussed, particularly in the exploration of oils, gases, and hydro-carbons, as well as in non-destructive testing, Mechanical Engineering, and Civil Engineering.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Acoustics
Jing Lu, Yu Xiang, Sha Chen, Hao Jin, ZhengXuan Chen
Summary: A new dynamic model for thin fluid-saturated porous rotational shells is proposed by combining the Biot theory and classical elastic theory. The first-order ordinary differential control equations are derived in the frequency domain and solved using the precise element method, demonstrating higher accuracy in the high-frequency range. The model's accuracy is verified through comparison with vibration experiments and equivalent property models.
SHOCK AND VIBRATION
(2021)
Article
Mathematics, Applied
Yoshiyuki Kagei, Hiroshi Takeda
Summary: The Cauchy problem for nonlinear elastic wave equations with viscoelastic damping terms is studied in the L-p framework, and sharp estimates of the global solutions for higher order derivatives are obtained. The proof involves a Gronwall type argument for 1 < p < infinity, the difference in propagation speed of the fundamental solutions for p = 1, the bootstrap argument for p = infinity, and sharp estimates for the linearized solutions.
JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS
(2023)
Article
Geochemistry & Geophysics
Roberto Miele, Dario Grana, Luiz Eduardo Seabra Varella, Bernardo Viola Barreto, Leonardo Azevedo
Summary: Accurate prediction of subsurface permeability is important for reservoir characterization and monitoring studies. Traditional approaches involve deterministic calculations or geostatistical methods, but we propose an iterative geostatistical seismic inversion method. This method combines rock-physics and geostatistical modeling, producing multiple realizations of facies, permeability, porosity, and acoustic impedance constrained by seismic data.
Article
Multidisciplinary Sciences
A. Roohezamin, R. Kalatehjari, M. Hajihassani, M. Kharghani, D. Dias
Summary: Understanding the acoustic behavior of buried tunnels in multilayer soil structures is crucial for locating and monitoring their structure health. This study presents a 3D finite element model of a tunnel system and investigates the variations in reflected and transmitted acoustic wave pressure for a multilayer soil buried tunnel. The effects of soil layers, tunnel buried depths, and lining concrete types on the acoustic wave behavior of the tunnel are evaluated. The findings can be applied to interpret recorded signals for structural health monitoring and locating underground structures, especially in media with multilayer soil structures.
SCIENTIFIC REPORTS
(2022)
Article
Astronomy & Astrophysics
Xiongdong Yu, Zhigang Yuan, Zhihai Ouyang, Fei Yao
Summary: This study used an analytical approximation method to examine the propagation of fast magnetosonic waves near the plasmapause boundary layer and provided analytical solutions for the electromagnetic fields of MS waves passing through this boundary layer. Theoretical calculations and observations have shown that electric fields of MS waves decrease rapidly while magnetic fields increase rapidly when crossing the plasmapause boundary layer. Parameter analysis suggests that a significant portion of waves will be reflected when the plasmapause boundary layer is narrow compared to the wavelength of MS waves.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Acoustics
Jiang Xie
Summary: This study presents an analytical solution for the inner soil impedance of saturated soil to a horizontally vibrating large-radius pipe pile. Through numerical examples, the variation of inner soil impedance with different factors was analyzed, and the pile radius corresponding to effective inner soil impedance was determined.
SHOCK AND VIBRATION
(2021)
Article
Physics, Applied
Xiaotian Xu, Michael Newns, Mark Oxborrow
Summary: This paper presents a method for simulating coupled electromagnetic and mechanical vibrations on arbitrarily shaped piezoelectric structures. The method is based on weak forms and can be implemented in any finite-element-method software, allowing accurate simulation of the flow of electromagnetic energy inside and around structures containing piezoelectric materials.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Acoustics
Omar Asfar, Bruno Morvan
Summary: Shear wave excitation of a triangular solid bar reveals the existence of horizontally polarized (SH) and vertically polarized (SV) shear waves. The SH waves are obtained from superposition of plane waves and their reflections. The SV waves are related to sub triangles and their cutoff wavenumbers lie between those of the Neumann SH modes. Dispersion curves confirm the correct cutoff wavenumbers of both SH and SV waves.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Physics, Mathematical
Xi Chen
Summary: This article constructs the resolvent of the Laplacian at high energies near the spectrum on non-product conic manifolds with a single cone tip. Microlocally, the resolvent kernel is the sum of b-pseudodifferential operators, scattering pseudodifferential operators, and intersecting Legendrian distributions. As an application, Strichartz estimates for Schrodinger equations on non-compact manifolds with multiple non-product conic singularities are established.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Mathematics, Applied
Yan Liu, Jincheng Shi
Summary: This paper investigates the asymptotic behavior, smoothing effect, and decay properties of solutions to coupled plate equations, utilizing Fourier analysis to approximate the solutions.
ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND PHYSIK
(2022)
Article
Acoustics
Georgios Sarris, Stewart G. Haslinger, Peter Huthwaite, Peter B. Nagy, Michael J. S. Lowe
Summary: This study uses high-fidelity two-dimensional finite element modeling to validate existing predictions and provide a unified approach to studying the problem of Rayleigh wave scattering from rough surfaces. The results show good agreement between theory and finite element results in the Rayleigh and stochastic scattering regimes, with power relationships obtained through dimensional analysis and simulations in the geometric regime. The method used for deriving three-dimensional theory can be verified by the insights provided in this study.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2021)
Article
Acoustics
A. Palermo, B. Yousefzadeh, C. Daraio, A. Marzani
Summary: This study investigates the propagation of Rayleigh waves in a half-space coupled to a nonlinear metasurface, analyzing the effects of nonlinear interaction force and energy loss on wave dispersion. The research presents closed-form expressions to predict the dispersive characteristics of nonlinear Rayleigh waves, demonstrating how different types of nonlinearity affect spectral gaps in the metasurface and revealing spatial gaps induced by softening nonlinearity in dispersion curves.
JOURNAL OF SOUND AND VIBRATION
(2022)
