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the resonant column method is a well-established medium-frequency wave propagation technique for the dynamic characterization of soils. this study presents an evaluation of young's modulus of a quartzitic sand derived from flexural resonant column tests. the results are compared with extender elements, which are embedd... | evaluating use of resonant column in flexural mode for dynamic characterization of bangalore sand |
in this paper, a new heterostructure phononic crystal is introduced. the new heterostructure is composed of square and rhombus phononic crystals. using finite difference method, a displacement-based algorithm is presented to study elastic wave propagation in the phononic crystal. in contrast with conventional finite di... | presentation and investigation of a new two dimensional heterostructure phononic crystal to obtain extended band gap |
with the growing demand from industry to optimize and further develop existing non-destructive testing & evaluation (ndt&e) techniques or new methods to detect and characterize incipient damage with high sensitivity and increased quality, ample efforts have been devoted to better understand the typical behavior... | non-destructive evaluation of kissing bonds using local defect resonance (ldr) spectroscopy: a simulation study |
non-collinear nonlinear ultrasonic (ncnlu) wave mixing technique has been established to study the localized plastic deformation at the crack tip during fatigue. a pair of ultrasonic shear wave was mixed non-collinearly to obtain a longitudinal wave of frequency equal to the sum of the two shear wave frequencies under ... | development of a non-collinear nonlinear ultrasonic-based technique for the assessment of crack tip deformation |
in this study, we introduce and discuss features and improvements of the well-established stiffness matrix method that is used in simulation of wave propagation in layered media. more specifically, we present stiffness matrices for an acoustic layer and a vertically transverse isotropic (vti) viscoelastic soil layer. c... | stiffness matrices for fluid and anisotropic soil layers with applications in soil dynamics |
the damage effects of an underwater explosion have always been a crucial problem in the ship mechanics. notably, the bubble evolution and the jet impact load are one of the most difficult parts in the shock-resistance design of ship structures due to the discontinuities and significant nonlinear deformation. in this pa... | jet development and impact load of underwater explosion bubble on solid wall |
coal-supercritical co2 (s-co2) interaction causes severe mechanical alterations in coal that can possibly affect the mechanical competency and the coal seam integrity. conventional static mechanical testings often fail to conduct repetitive and temporal measurements on coal specimens in the process of coal-s-co2 intera... | characterization of dynamic mechanical alterations of supercritical co2-interacted coal through gamma-ray attenuation, ultrasonic and x-ray computed tomography techniques |
freshwater fluxes from melting icebergs and glaciers are important contributors to both sea level rise and anomalies of seawater salinity in polar regions. however, the hazards encountered close to icebergs and glaciers make it difficult to quantify their melt rates directly, motivating the development of cryoacoustics... | the intensity, directionality, and statistics of underwater noise from melting icebergs |
among the baseline-free damage detection techniques based on guided waves (gws), instantaneous baseline measurement is easily applied in practical situations. however, the number of transducers increases when large structures are inspected, and the operation becomes quite complicated because the excitation signal has t... | an improved instantaneous baseline method for pipe structures based on distance compensation using guided waves |
a novel numerical approach is proposed herein to study thermomechanical wave propagation in annular disks made of viscoelastic materials under inner thermal shock based on the lord-shulman (l-s) theory and the kelvin-voigt model. it is assumed that the temperature change is considerable in comparison with the reference... | thermally nonlinear generalized coupled thermo-viscoelasticity of disks: a numerical variational approach |
coherent wave-propagation in the near-field fresnel-regime is the underlying contrast-mechanism to (propagation-based) x-ray phase contrast imaging (xpci), an emerging lensless technique that enables 2d- and 3d-imaging of biological soft tissues and other light-element samples down to nanometer-resolutions. mathematica... | locality estimates for fresnel-wave-propagation and stability of x-ray phase contrast imaging with finite detectors |
we have developed a new technique for determining the liquidus and eutectic (or solidus) temperatures of fe-light element alloys at high pressures in a multianvil apparatus, by studying ultrasonic wave propagation through the sample. while the onset of melting is manifested by the loss of both compressional (p-) and sh... | pressure dependence of the liquidus and solidus temperatures in the fe-p binary system determined by in situ ultrasonics: implications to the solidification of fe-p liquids in planetary cores |
the reflection-mode digital gradient sensing (r-dgs) method is extended to visualize and quantify dynamic deformations in solids due to stress wave propagation and for damage/disbond detection in layered materials due to impact loading. the r-dgs technique employs digital image correlation principles to quantify two or... | extension of reflection-mode digital gradient sensing method for visualizing and quantifying transient deformations and damage in solids |
we study primary pulse transmission in a two-dimensional granular network composed of two ordered chains that are nonlinearly coupled through hertzian interactions. impulsive excitation is applied to one of the chains (designated as 'excited chain'), and the resulting transmitted primary pulses in both chains are consi... | nonlinear mixed solitary-shear waves and pulse equi-partition in a granular network |
starting in 2014 december, kepler k 2 observed neptune continuously for 49 days at a 1 minute cadence. the goals consisted of studying its atmospheric dynamics, detecting its global acoustic oscillations, and those of the sun, which we report on here. we present the first indirect detection of solar oscillations in int... | a distant mirror: solar oscillations observed on neptune by the kepler k2 mission |
context. asymptotic giant branch (agb) stars are characterized by substantial mass loss, however the mechanism behind it not yet fully understood. the knowledge of the structure and dynamics of agb-star atmospheres is crucial to better understanding the mass loss. the recently established tomographic method, which reli... | tomography of cool giant and supergiant star atmospheres. iii. validation of the method on vlti/amber observations of the mira star s ori |
we describe compressible two-phase flows by a single-velocity six-equation flow model, which is composed of the phasic mass and total energy equations, one volume fraction equation, and the mixture momentum equation. the model contains relaxation source terms accounting for volume, heat and mass transfer. the equations... | arbitrary-rate relaxation techniques for the numerical modeling of compressible two-phase flows with heat and mass transfer |
a breakwater model is developed to analyse the wave propagation over an asymmetric rectangular trench in presence of two thin vertical partially immersed barriers. with the help of eigenfunction expansion, the problem is reduced to four weakly singular integral equations involving horizontal component of velocity acros... | oblique wave interaction by two thin vertical barriers over an asymmetric trench |
typical areas of application of explicit dynamics are impact, crash test, and most importantly, wave propagation simulations. due to the numerically highly demanding nature of these problems, efficient automatic mesh generators and transient solvers are required. to this end, a parallel explicit solver exploiting the a... | a massively parallel explicit solver for elasto-dynamic problems exploiting octree meshes |
quantitative and reliable monitoring of osseointegration will help further evaluate the integrity of the orthopaedic construct to promote novel prosthesis design and allow early mobilisation. quantitative assessment of the degree or the lack of osseointegration is important for the clinical management with the introduc... | a quantitative approach for the bone-implant osseointegration assessment based on ultrasonic elastic guided waves |
we have proposed a quantitative shear wave imaging technique for continuous shear wave excitation. shear wave wavefront is observed directly by color flow imaging using a general-purpose ultrasonic imaging system. in this study, the proposed method is applied to experiments in vivo, and shear wave maps, namely, the she... | shear wave mapping of skeletal muscle using shear wave wavefront reconstruction based on ultrasound color flow imaging |
we propose a nonlinear ultrasonic technique by using the mixed-frequency signals excited lamb waves to conduct micro-crack detection in thin plate structures. simulation models of three-dimensional (3d) aluminum plates and composite laminates are established by abaqus software, where the aluminum plate contains buried ... | micro-crack detection of nonlinear lamb wave propagation in three-dimensional plates with mixed-frequency excitationyg |
the solution of the complete three-dimensional (3d) guided wave propagation problem in infinite laminated composite plates using a semi-analytical method is presented. the proposed method constructs the problem directly from the 3d governing equations, assuming through-the-thickness layerwise laminate mechanics with li... | a layerwise semi-analytical method for modeling guided wave propagation in laminated composite infinite plates with induced surface excitation |
source location determination of volcanic tremor has been a challenge in seismology due to the waveform complexity and difficulties in reading p- and s-wave arrival times. we present a method for locating volcanic tremor recorded at a seismic network distributed around a volcano. the method combines the source-scanning... | reliability evaluation of volcanic tremor source location determination using cross-correlation functions |
insects are key laboratory models for research on the fitness effects, genetics and plasticity of senescence. it was long believed that insects almost never survive long enough to senesce in the wild, but it is now clear that senescence occurs and can exact substantial fitness costs in natural insect populations. yet, ... | senescence in wild insects: key questions and challenges |
the objects of consideration are thin linearly elastic kirchhoff-love-type circular cylindrical shells having a periodically micro-heterogeneous structure in circumferential direction (uniperiodic shells). the aim of this contribution is to study certain problems of micro-vibrations and of wave propagation related to m... | on the cell-dependent vibrations and wave propagation in uniperiodic cylindrical shells |
numerical shock instability is a common problem for shock-capturing methods that try to resolve contact and shear waves with minimal diffusion. most flux-difference splitting and the ausm family of schemes produce the carbuncle phenomenon on both structured and unstructured grids. the original roe scheme is well known ... | a stable hybrid roe scheme on triangular grids |
knowledge of the position of lithological boundaries is key information for a realistic interpretation of geological settings. especially in the mining environment, the exact knowledge of geometrical boundaries and characteristics of rock structures has a great impact for both economic decisions and safety awareness. f... | mapping lithological boundaries in mines with array seismology and in situ acoustic emission monitoring |
this study proposes a new line laser lock-in thermography (llt) technique for instantaneous inspection of surface cracks in semiconductor chips. first, a new line llt system is developed by integrating a line scanning laser source, a high-speed infrared (ir) camera with a close-up lens, and a control computer. the prop... | line laser lock-in thermography for instantaneous imaging of cracks in semiconductor chips |
plasmonic nanocomposites have been extensively studied for over 3 decades. according to early theoretical studies, a large enhancement of nonlinear response has been predicted. nonetheless, the promised enhancement of coherent or kerr-type nonlinearities incurs major limitations related to strong absorption and saturat... | nonlinear propagation of laser light in plasmonic nanocomposites |
we studied regular diurnal and seasonal behaviors of ground backscatter propagation characteristics corresponding to the hokkaido east super dual auroral radar network (superdarn) (43.53° n, 143.61° e). firstly, we simulated key propagation characteristics using a high frequency (hf) calculation technique based on the ... | diurnal and seasonal behavior of the hokkaido east superdarn ground backscatter: simulation and observation |
in this paper, we investigate the flexural elastic wave propagation properties in phononic crystals (pcs) consisting of co-axial steel and electrorheological (er) elastomer pillars deposited on a thin plate. the finite element method and the super cell technique are used to calculate the band structures and transmissio... | tuning flexural elastic wave propagation in electroactive phononic crystals |
plasma sheath can potentially degrade global navigation satellite system (gnss) through signal attenuation as well as phase noise when a hypersonic vehicle reenters the earth's atmosphere. modeling and simulation method of gnss system disturbed by plasma sheath is introduced in this paper by means of electromagnetic wa... | the modeling and simulation of plasma sheath effect on gnss system |
solidly mounted resonators (smrs) with an acoustic bragg reflector should be more suitable for high power rf filters than a self-standing structure because heat can be transferred to the supporting substrate. thus, even though the demand for smrs is expected to increase, the evaluation of the properties of the bragg re... | a method for extracting sole mechanical properties of bragg reflector by ghz ultrasonic pulse-echo technique |
microwave radar sensors have been developed for non-contact monitoring of the health condition and location of targets, which will cause minimal discomfort and eliminate sanitation issues, especially in a pandemic situation. to this end, several radar sensor architectures and algorithms have been proposed to detect mul... | recent development of non-contact multi-target vital sign detection and location tracking based on metamaterial leaky wave antennas |
the evolution and characteristics of induced seismicity in geothermal stimulations can shed light on water pathways and fracture network development. however, these seismic sources are usually difficult to characterize due to their small magnitudes and the low signal-to-noise ratio (snr) of observational recordings. he... | array based analysis of induced earthquake characteristics using beamforming and back-projection methods in helsinki, finland |
we investigate linear, thermoelastic wave propagation in a layered piezoelectric material composed of a slab bonded to a half-space substrate of a dissimilar material, within dual-phase-lag model and under thermomechanical loads. one of the aims of the present work is to formulate a set of boundary conditions that is c... | thermoelastic wave propagation in a piezoelectric layered half-space within the dual-phase-lag model |
timber utility poles are significantly used in power and telecommunication infrastructures all over the world. the deterioration of timber with time is common due to various factors including termite attacks and climatic conditions. failure of poles can have serious safety concerns and economic implications. hence, the... | condition assessment tool for timber utility poles using stress wave propagation technique |
gravity waves play an important role in the propagation of energy and momentum from the lower atmospheric regions into the upper atmosphere. depending on the varying dissipation conditions, these waves generated in the lower atmosphere can propagate higher into the atmosphere. as the neutrals and plasma share the same ... | changes in the daytime thermospheric gravity wave propagation characteristics over low-latitudes in response to the variation in solar flux |
in this paper, we studied the (3 + 1)-dimensional nonlinear kadomtsev-petviasvili equation (3d-kpe) that is utilized in order to describe 3d solitons in weakly dispersive media, long wavelength water waves with weak nonlinear restoring forces, waves in ferromagnetic media, nonlinear wave propagation in supefluids, plas... | soliton solutions to the nonlinear higher dimensional kadomtsev-petviashvili equation through the new kudryashov's technique |
cracks universally exist in earth's crustal rocks. many rocks are intrinsically anisotropic, which, when coupled with crack-induced anisotropy, significantly affect seismic wave propagation through the rocks. using the method of sphere equivalency of effective scattering, we have developed a technique to model the effe... | seismic shear wave anisotropy of an anisotropic rock containing aligned cracks: theory and applications to experiment and field data |
the phenomenon, known as a complete band gap in photonic crystals consisting of periodically arranged manmade nanostructures, caused a huge sensation in photonics. inspired by the physical methodology, we extend it to large-scale wave propagation for seismic waves. in particular, we exploit the elastodynamic navier equ... | seismic phononic crystals by elastodynamic navier equation |
a porous-core circular photonic crystal fiber is designed for low-loss terahertz (thz) wave propagation. the circular arrangement of air holes, both in the periodic cladding and the porous core, makes it possible to guide most of the optical power through low-loss air, which is confirmed by the rigorous analysis of mod... | dispersion flattened, low-loss porous fiber for single-mode terahertz wave guidance |
coda waves interferometry (cwi) aims at tracking small changes in solid materials like rocks where elastic waves are diffusing and so intensively sampling the medium, making the technique more sensitive than those relying on direct wave arrivals. its application to ambient seismic noise correlation, referred to as ambi... | direct modeling of the mechanical strain influence on coda wave interferometry |
due to the complexity of components and damage mechanism of reinforced concrete, the wave propagation characteristics in reinforced concrete are always complicated and difficult to determine. the objective of this article is to study the failure process of reinforced concrete structure under the damage caused by pencil... | propagation characteristics of acoustic emission wave in reinforced concrete |
microwave reflectometry techniques have been successfully applied to measure electron density fluctuations in magnetic confined fusion devices with good spatial and time resolutions. however, quantitative interpretation of turbulence measurements has driven continuous development of both analytical theory and sophistic... | synthetic conventional reflectometry probing of edge and scrape-off layer plasma turbulence |
diagnosing plasma conditions can give great advantages in optimizing plasma wakefield accelerator experiments. one possible method is that of photon acceleration. by propagating a laser probe pulse through a plasma wakefield and extracting the imposed frequency modulation, one can obtain an image of the density modulat... | quantitative single shot and spatially resolved plasma wakefield diagnostics |
this paper presents the study of applying the nonlinear ultrasonic wave to evaluate the stress state of metallic materials under steady state. the pre-stress loading method is applied to guarantee components with steady stress. three kinds of nonlinear ultrasonic experiments based on critically refracted longitudinal w... | stress evaluation of metallic material under steady state based on nonlinear critically refracted longitudinal wave |
context. large-scale flows in the sun play an important role in the dynamo process linked to the solar cycle. the important large-scale flows are the differential rotation and the meridional circulation with an amplitude of km s-1 and few m s-1, respectively. these flows also have a cycle-related components, namely the... | large-scale photospheric motions determined from granule tracking and helioseismology from sdo/hmi data |
we develop a general theoretical approach to describing the interaction of metamaterials with optical beams. the metamaterials are allowed to be anisotropic, chiral, noncentrosymmetric, and spatially dispersive. unlike plane waves, beams can change their field distributions upon interaction with metamaterials, which ca... | interaction of metamaterials with optical beams |
tip vortex cavitation (tvc) is an important cavitation phenomenon in marine propeller. the formation and evolution of tip vortex cavitation are hot topics consistently both in engineering application and mechanism research. in this paper some recent studies on tip vortex cavitation inception and the noise of tip vortex... | study of tip vortex cavitation inception and vortex singing |
different from cauchy elastic materials, generalized continua, and in particular constrained cosserat materials, can be designed to possess extreme (near a failure of ellipticity) orthotropy properties and in this way to model folding in a three-dimensional solid. following this approach, folding, which is a narrow zon... | the dynamics of folding instability in a constrained cosserat medium |
modern geophysical imaging techniques exploit the full wavefield information which can be simulated numerically. these numerical simulations are computationally expensive due to several factors, such as a large number of time steps and nodes, big size of the derivative stencil and huge model size. besides these constra... | an algorithm for fast elastic wave simulation using a vectorized finite difference operator |
we evaluated the prospects of quantifying the parameterized post-newtonian parameter β and solar quadrupole moment {j}2⊙with observations of near-earth asteroids with large orbital precession rates (9 to 27 arcsec century-1). we considered existing optical and radar astrometry, as well as radar astrometry that can real... | prospects of dynamical determination of general relativity parameter β and solar quadrupole moment {j}_{2\\odot } with asteroid radar astronomy |
we present a flux vector splitting method for the one and two-dimensional shallow water equations following the approach first proposed by toro and vázquez for the compressible euler equations. the resulting first-order schemes turn out to be exceedingly simple, with accuracy and robustness comparable to that of the so... | a flux-vector splitting scheme for the shallow water equations extended to high-order on unstructured meshes |
the structure and magnetic properties of rare-earth ions tm3+ kagomé lattice tm3sb3mg2o14 are studied by x-ray diffraction, magnetic susceptibility and muon spin relaxation (μsr) experiments. the existence of a small amount of tm/mg site-mixing disorder is revealed. dc magnetic susceptibility measurement shows that tm3... | muon spin relaxation study of frustrated tm3sb3mg2o14 with kagomé lattice |
a tapered nanobeam is modelled by euler-bernoulli beam theory and nonlocal theory of elasticity. a solution technique based on homotopy perturbation method is proposed to analyse the dynamic behavior of the tapered nanobeam. beam becomes tapered along the width exponentially. the effects of flexible and rigid supports ... | transverse vibration of tapered nanobeam with elastic supports |
conventional ultrasonography reconstruction techniques, such as b-mode, are based on a simple wave propagation model derived from a high frequency approximation. therefore, to minimize model mismatch, the central frequency of the input pulse is typically chosen between 3 and 15 megahertz. despite the increase in theore... | ultrasound breast imaging using frequency domain reverse time migration |
there are a variety of approaches used to create elastography images. techniques based on shear wave propagation have received significant attention. however, there remain some limitations and problems due to shear wave reflections, limited penetration in highly viscous media, requirements for prior knowledge of wave p... | reverberant shear wave elastography: a multi-modal and multi-scale approach to measure the viscoelasticity properties of soft tissues |
phase transitions in liquid benzene under laser shocked conditions are studied using high-resolution time-resolved raman spectroscopic technique. the c-c ring breathing mode (υ1) of benzene at 993 cm−1 is analyzed to monitor the phase transitions occurring in the raman spectra during shock wave propagation in the press... | phase transitions in benzene under dynamic and static compression |
the primary objective of this study is to introduce a stochastic framework based on generalized polynomial chaos (gpc) for uncertainty quantification in numerical ocean wave simulations. the techniques we present can be easily extended to other numerical ocean simulation applications. we perform stochastic simulations ... | stochastic simulations of ocean waves: an uncertainty quantification study |
we consider the long-time instability issue associated with finite difference simulation of seismic acoustic wave equations on discontinuous grids. this issue is exhibited by a prototype algebraic problem abstracted from practical application settings. analysis of this algebraic problem leads to better understanding of... | on long-time instabilities in staggered finite difference simulations of the seismic acoustic wave equations on discontinuous grids |
for simple, safe, portable, and inexpensive evaluation suitable for leg bone diseases of racehorses in the field, an ultrasonic measurement technique was applied to evaluate wave velocities. a digital model of the third metacarpal bone with the bucked shin was fabricated using high-resolution peripheral quantitative co... | study on ultrasonic wave propagation in equine leg bone for screening bucked shin |
context. information carried by the full wave field is particularly important in applications involving wave propagation, backpropagation, and a sparse distribution of measurement points, such as in tomographic imaging of a small solar system body.aims: with this study, our aim is to support the future mission and expe... | analysis of full microwave propagation and backpropagation for a complex asteroid analogue via single-point quasi-monostatic data |
the general transmissivity law of ground vibrations was studied, and a user-friendly methodology for determining the behavior of vibrations generated in any rock mass is proposed. the study was based on a single blast in a trench excavation, analyzing the vibration components recorded from two fixed locations. the atte... | determination of the ground vibration attenuation law from a single blast: a particular case of trench blasting |
piezoelectric transformers can be a promising candidate in isolated power converters to replace magnetic ones as they present high quality factor, high voltage gain and low electromagnetic compatibility issues. herein a new topology of traveling wave piezoelectric transformer (twpt) is proposed. unlike conventional pie... | a transverse traveling wave piezoelectric transformer |
wave propagation and diffusive transport phenomena are influenced by the mechanical discontinuities in material. this study shows that certain bulk properties of the network of low-velocity mechanical discontinuities (e.g. air-filled cracks) in a material can be characterized by processing compressional-wave travel tim... | characterization of mechanical discontinuities based on data-driven classification of compressional-wave travel times |
ground motion prediction is important for earthquake early warning systems, because the region's peak ground motion indicates the potential disaster. in order to predict the peak ground motion quickly and precisely with limited station wave records, we propose a real-time numerical shake prediction and updating method.... | real-time numerical shake prediction and updating for earthquake early warning |
deep geological repositories, isolated from the geosphere by an engineered bentonite barrier, are currently considered the safest solution for high-level radioactive waste (hlrw) disposal. as the physical conditions and properties of the bentonite barrier are anticipated to change with time, seismic tomography was sugg... | attenuation of elastic waves in bentonite and monitoring of radioactive waste repositories |
backprojection has proven useful in imaging large earthquake rupture processes. the method is generally robust and requires relatively simple assumptions about the fault geometry or the earth velocity model. it can be applied in both the time and frequency domain. backprojection images are often obtained from records f... | frequency-difference backprojection of earthquakes |
this article discusses the ultrasonic method for monitoring the strength of concrete in piles. geotechnical conditions of the city territory are indicated. the conditions of hardening of the concrete mixture in the pile shaft and the normal conditions of hardening of concrete samples are described. a detailed descripti... | ultrasonic testing of concrete hardening in pile foundations |
the nonlinear fractional model, videlicet, the space-time fractional (2+1)-dimensional fractional bogoyavlenskii equations is an important nonlinear mathematical model to elucidate the hydrodynamic model of shallow water wave, plasma physics, the wave of leading fluid flow etc. this paper is devoted to studying the dyn... | analytical behavior of the fractional bogoyavlenskii equations with conformable derivative using two distinct reliable methods |
in this paper, studies on dynamic modeling, simulation and experiment of power transmission belt drives are comprehensively reviewed. in the past few decades, many investigations are conducted on dynamic modeling, simulation and experiment of different kinds of power transmission belt drive systems. in the dynamic mode... | dynamic modeling, simulation and experiment of power transmission belt drives: a systematic review |
in this paper, the propagation of stress waves in thick porous graphene-reinforced cylinders (tpgrcs) is investigated using a meshless solution based on an axisymmetric model and moving least squares (mlss) interpolation functions. the cylinders are assumed under a steady state thermal gradient effect along with an ini... | stress waves in thick porous graphene-reinforced cylinders under thermal gradient environments |
crack microgeometry vitally influences effective elastic characteristics and sonic responses. researchers commonly employ seismic-wave-based exploration methods to assess and interpret fracture attributes. numerical simulation, as a promising way for this issue, still faces some challenges. with the rapid development o... | modeling seismic responses in complex fractured media using the modified lattice spring model coupled with discrete fracture networks |
in the present study, propagation of magnetoelastic shear wave due to a momentary point source in a viscoelastic crustal layer over inhomogeneous viscoelastic half space has been discussed. green's function technique and fourier transform along with method of successive approximation are used to find the closed-form so... | modeling of magnetoelastic shear waves due to point source in a viscoelastic crustal layer over an inhomogeneous viscoelastic half space |
structural health monitoring systems for composite laminates using guided ultrasonic waves become more versatile with the structural integration of sensors. however, the data generated within these sensors have to be transmitted from the laminate to the outside, where polyimide-based printed circuit boards play a major... | influence of a flat polyimide inlay on the propagation of guided ultrasonic waves in a narrow gfrp-specimen |
in this study, we report a new energy dissipation mechanism of nanomechanical resonators due to the casimir effect originating from quantum fluctuation of the vacuum electromagnetic field at the nanoscale. an analytical study on the evaluation of the casimir effect-induced energy loss in nanobeam resonators undergoing ... | a new mechanism of energy dissipation in nanomechanical resonators due to the casimir force |
nonlinear wave propagation is studied in a dissipative, self-gravitating bose-einstein condensate, starting from the gross-pitaevskii equation. in the absence of an exact analytical result, approximate methods like the linear analysis and perturbative approach are applied. the linear dispersion relation puts a restrict... | dissipative nonlinear waves in a gravitating quantum fluid |
this article presents the results of observation of extremely low frequency (elf, 300-3000 hz) electromagnetic radiation related to seismic activity in the period before and after strong m6.0 earthquake. proper elf radiation of the system of tectonic faults may indicate the state of activity and help to understand and ... | elf radio emission associated with strong m6.0 earthquake |
in the present paper, a mathematical model studying the effect of smooth moving semi-infinite punch on the propagation of love-type wave in an initially stressed viscoelastic strip is developed. the dynamic stress concentration due to the punch for the force of a constant intensity has been obtained in the closed form.... | love-type wave propagation in a pre-stressed viscoelastic medium influenced by smooth moving punch |
in acoustic power transfer systems, a receiver is displaced from a transmitter by an axial depth, a lateral offset (alignment), and a rotation angle (orientation). in systems where the receiver’s position is not fixed, such as a receiver implanted in biological tissue, slight variations in depth, orientation, or alignm... | a computationally efficient technique to model depth, orientation and alignment via ray tracing in acoustic power transfer systems |
through the use of a reductive perturbation technique, solitary kinetic alfvén waves (kaws) are investigated in a low but finite β (particle-to-magnetic pressure ratio) dense electron-positron-ion plasma where electrons and positrons are degenerate. the degenerate plasma model considered here permits the existence of s... | solitary kinetic alfvén waves in a dense electron-positron-ion plasma with degenerate electrons and positrons |
theoretical investigations are carried out for the cylindrical and spherical dust-ion acoustic solitary waves with the kinematic viscosity. by the reductive perturbation technique the damped kdv-burgers equation is obtained, and an approximate analytical solution is given. using this solution, the effects of different ... | cylindrical and spherical dust-ion acoustic solitary waves by damped korteweg-de vries-burgers equation |
phononic crystals (pncs) and n-type doped silicon technique have been widely employed in silicon-based mems resonators to obtain high quality factor (q) as well as temperature-induced frequency stability. for the pncs, their band gaps play an important role in the acoustic wave propagation. also, the temperature and do... | a phononic crystal strip based on silicon for support tether applications in silicon-based mems resonators and effects of temperature and dopant on its band gap characteristics |
to verify the performance of longitudinal waves induced by laser phased arrays (lpa) for detection and quantitative evaluation in internal defects, the finite element method (fem) is utilized to establish the models of lpa scanning processing. the interaction of longitudinal wave and internal defect is analyzed. beside... | numerical simulation of internal defect imaging with the longitudinal wave generated by laser induced ultrasonic array |
the elastodynamic response of finite 3d phononic structures is analyzed by means of comparing experimental findings obtained through a laser doppler vibrometry-based methodology and theoretical computations performed with the layer-multiple-scattering method. the recorded frequency-gap spectrum of the phononic slabs ex... | elastodynamic response of three-dimensional phononic crystals using laser doppler vibrometry |
solving evolutionary equations in a parallel-in-time manner is an attractive topic and many algorithms are proposed in recent two decades. the algorithm based on the block $\alpha$-circulant preconditioning technique has shown promising advantages, especially for wave propagation problems. by fast fourier transform for... | stability implies robust convergence of a class of preconditioned parallel-in-time iterative algorithms |
accurate simulation of nonlinear acoustic waves is essential for the continued development of a wide range of (high-intensity) focused ultrasound applications. this article explores mixed finite element formulations of classical strongly damped quasilinear models of ultrasonic wave propagation; the kuznetsov and wester... | mixed approximation of nonlinear acoustic equations: well-posedness and a priori error analysis |
in this paper, an algebraic reconstruction technique is presented for corrosion damage monitoring in steel pipes by using helical guided ultrasonic waves. to validate the proposed approach, numerical simulations as well as experimental tests were carried out. for the numerical simulations, a finite element model was cr... | an algebraic reconstruction imaging approach for corrosion damage monitoring of pipelines |
a relevant application of transformation elastodynamics has shown that flexural waves in a kirchhoff-love plate can be diverted and channeled to cloak a region of the ambient space. to achieve the goal, an orthotropic meta-structural plate should be employed. however, the corresponding mathematical transformation leads... | numerical assessment of the performance of elastic cloaks for transient flexural waves |
control of structural topology, via a bottom-up approach, is now possible through the advent and continuing maturation of additive manufacturing techniques. for example, new classes of porous materials with increased strength-to-density ratios, novel thermal and acoustic properties, and even "metamaterial" properties s... | shockwave interactions with additively-manufactured polymer structures |
the negative pressure wave propagation method is an established structural health monitoring (shm) technique to locate leakages and defects in pipelines. the amplitude of negative pressure waves can be exploited to obtain information about the severity of the damage (e.g. leak flow rate and leak area) and are useful to... | an analytical amplitude model for negative pressure waves in gaseous media |
we develop a technique for finding closed-form expressions for electromagnetic fields in radially inhomogeneous bianisotropic media, both the solutions of the maxwell equations and material tensors being defined by the set of auxiliary two-dimensional matrices. the approach is applied to determine the scattering cross-... | spherically symmetric inhomogeneous bianisotropic media: wave propagation and light scattering |
the accurate measurement of the prestress for bolt has been intensively investigated in recent years. many research studies have been conducted to improve the accuracy of prestress measurement using ultrasound techniques; in particular, the real-time prestress of bolt can be obtained without the requirements to calibra... | zno piezoelectric coatings used for the ultrasonic excitation of longitudinal-transverse waves and their application for smart bolts |
bloch mode synthesis (bms) is a model order reduction method that was originally formulated to accelerate band-structure calculations of periodic elastic materials. in this paper, the bms framework is expanded to offer a platform suitable for analysis of electroelastic metamaterials with piezoelectric resonant shunt da... | a refined bloch mode synthesis framework for fast and accurate analysis of electroelastic metamaterials with piezoelectric resonant shunt damping |
while several mm-wave and sub-thz frequency bands are being proposed for next generation wireless systems to meet the increasing traffic demand, the electromagnetic properties of many common use materials at those frequencies still need to be determined. the evaluation of such properties is important for the design and... | improved fabry-pérot electromagnetic material characterization: application and results |
the pipeline system is the most important part in media transport in order to deliver fluid to another station. the weak maintenance and poor safety will contribute to financial losses in term of fluid waste and environmental impacts. there are many classifications of techniques to make it easier to show their specific... | leak detection in gas pipeline by acoustic and signal processing - a review |
two-dimensional (2d) ultrasound shear wave elastography (swe) has been widely used for soft tissue properties assessment. given that shear waves propagate in three dimensions (3d), extending swe from 2d to 3d is important for comprehensive and accurate stiffness measurement. however, implementation of 3d swe on a conve... | three-dimensional shear wave elastography on conventional ultrasound scanners with external vibration |
high-order numerical methods for solving time-dependent acoustic-elastic coupled problems are introduced. these methods, based on finite element techniques, allow for a flexible coupling between the fluid and the solid domain by using non-conforming meshes and curved elements. since characteristic waves travel at diffe... | non-conforming curved finite element schemes for time-dependent elastic-acoustic coupled problems |
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