Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 24 for “"Rayleigh waves"”.
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Rayleigh waves from mid-ocean ridge earthquakes : source and path effects
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Earth and Planetary Science, 1972
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Source and propagation effects of Rayleigh waves from Central Asian earthquakes.
Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Science.
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The anelastic structure and deep geology of the Derbyshire Dome from high frequency Rayleigh waves.
… high frequency, 0.6 - 4.2 Hz, fundamental mode Rayleigh waves observed from quarry blasts within the study area. Seismic field experiments, designed and implemented to record Rayleigh waves accurately, are discussed together with the data preparation sequence. The effects of possible errors on …
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A global study on phase velocity, group velocity and attenuation of Rayleigh waves in the period range 20 to 100 seconds
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1987.
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Experimental investigation of near-field effects on the SASW dispersion curve
… any method of surface wave testing that involves Rayleigh waves is performed, one important assumption is that plane Rayleigh waves are being measured. In the forward modeling or inversion procedure that is used to analyze the field dispersion curve to determine the field V[subscript s] profile, …
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Anisotropy and the structural evolution of the oceanic upper mantle
The dispersion of Love and Rayleigh waves in the period range 17-167 sec. is used to detect the change in the structure of the upper mantle as the age of the sea-floor increases away from the mid-ocean ridge. Using the single station method, the group and phase velocities of Rayleigh waves were …
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Surface Acoustic Waves Propagation and Coupling Fields in Piezomagnetic and Piezoelectric Semiconductor Layered Structures
… research on multi-field coupling behaviors and waves modulation of PSs has become one of the hot topics. By integrating multiferroic materials with PSs, new magnetically regulated composite devices such as magnetically induced piezoelectric potential transistors, magnetically driven …
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ΠΡΟΒΛΗΜΑΤΑ ΤΗΣ ΓΕΝΙΚΕΥΜΕΝΗΣ ΘΕΡΜΟΕΛΑΣΤΙΚΟΤΗΤΑΣ ΚΑΙ ΕΠΕΚΤΑΣΗ ΤΗΣ ΣΤΑ ΣΙΔΗΡΟΜΑΓΝΗΤΙΚΑ ΥΛΙΚΑ
… THE PROBLEM OF THE PROPAGATION OF THERMOELASTIC WAVES IN AN INFINITE CYLINDER IS STUDIED. (II) THE FIELD EQUATIONS AND THE BOUNDARY CONDITIONS OF LORD'S AND SHULMAN'S THEORY ARE GIVEN, EXTENDED IN THEMAGNETO-ELECTRO- THERMOELASTICITY FOR AN INITIALLY STRESSED MATERIAL. ON THE BASIS OF THE ABOVE …
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Multistation Methods for Geotechnical Characterization using Surface Waves
… cost effective. An overview of the properties of Rayleigh waves in layered linear elastic and linear viscoelastic media is presented, together with their applications for site characterization, of whose the SASW (Spectral Analysis of Surface Waves) method is by far the most well-known in …
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Asymptotic description of the acoustic microscopy of a surface-breaking crack
… surface. The latter wavefield contains the leaky Rayleigh wave that is incident to the surface-breaking crack. The surface-breaking crack is characterized by assigning it reflection and transmission coefficients. The wavefield scattered from the crack is estimated by tracing the leaky Rayleigh …
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Flexible Strain Detection Using Surface Acoustic Waves: Fabrication and Tests
… An RF input signal excites IDTs and generates Rayleigh waves that propagate through the delay line. By analyzing the changes in wave characteristics, such as frequency shift and phase response, the developed passive strain sensor can measure mechanical strains.</p>
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Surface wave techniques for the study of engineering structures and materials
… and this initiated the work on one dimensional Rayleigh waves.Their properties were established for the straight edge condition by following an analysis similar to that of the two dimensional case. Experiments were then carried out on the velocity dispersion of various circuits including the …
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The onset of gouging in high-speed sliding contacts
… while other models based on mechanisms such as Rayleigh waves, bending waves, and shear band formation were ruled out. An effective Reynolds number approach from explosive welding research was applied to gouging with encouraging results. Based on similarities between gouging, explosive welding, …
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The effect of shear on the stability and dynamic properties of elastic bodies
… motions provides the mechanism for analyzing Rayleigh waves propagating along the surface of an incompressible elastic half-space. This is looked at from a plane strain point of view but, significantly, the direction of propagation is not along a principal axis. Using co-ordinates measured …
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Ambient seismic noise tomography of the southern United States and seismic inversion with dictionary learning using unsupervised machine learning.
… and cross-coherence. This mimics Rayleigh wave phase characteristics. We address the problem of non-stationary phases in Rayleigh wave extraction from ambient noise. Seismic interferometry assumes stationary phase dominance in EGF estimation, but real-world, non-uniform source …
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Variable grid finite-difference modeling including surface topography
… due to the large grid sizes rather than the Rayleigh waves scattering due to the stair-shaped boundary. The finite-difference modeling is applied to the investigation of near surface wave propagation. Several numerical simulations are performed to show the characters of wave propagation in …
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Development to a Flexible Surface Acoustic Wave Sensor for Strain Sensing
… which transfers the signal in the form of Rayleigh waves. The frequency response of the SAW device changes in amplitude and phase when subjected to temperature, pressure, or strain changes. FEM model of the SAW sensor is conducted, and the resulting deformation simulation is performed. This …
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Ambient seismic noise imaging using trans-dimensional and machine learning techniques with application to Borneo and Iceland
… computed velocity models for both Vsh (from Love waves) and Vsv (from Rayleigh waves), along with associated uncertainties, which allowed radial anisotropy to be measured. This model reveals a pronounced low Vs anomaly at 1-3 km depth beneath the caldera, which I interpret to be the signature of a …
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Avalanching on dunes and its effects: Size statistics, stratification, & seismic surveys
… dune acts as a resonator, absorbing energy from Rayleigh waves and reemitting it over an extensive period of time. I derive and validate a mathematical framework that uses bulk properties of the dune to predict quantitative properties of the emitted waves, and I demonstrate the importance of …
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Velocity and anisotropy structure of the Icelandic crust - An ambient seismic noise analysis
Measuring the travel times of seismic waves is one of the most important tools for uncovering Earth’s structure and dynamics. In recent years, the discovery that surface wave dispersion could be estimated from ambient noise has introduced new possibilities into the field of seismic imaging, such as …
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