Rayleigh-wave phase velocity of a layered earth model is a function of frequency and four groups of earth properties: Pwave velocity, S-wave velocity (Vs), density, and thickness of layers. Analysis of the Jacobian matrix (or the difference method) provides a measure of dispersion curve sensitivity to earth properties. Vs is the dominant influence for the fundamental mode (Xia et al., 1999) and...

Applying corona wind as a novel technique can lead to a great level of heat and mass transfer augmentation by using a very small amount of energy. The enhancement of forced flow evaporation rate by applying electric field (corona wind) has been experimentally evaluated in this study. Corona wind produced by a fine wire electrode charged with positive high DC voltage impinges on water surface an...

shear wave velocity (vs) data are key information for petrophysical, geophysical and geomechanical studies. although compressional wave velocity (vp) measurements exist in almost all wells, shear wave velocity is not recorded for most of elderly wells due to lack of technologic tools. furthermore, measurement of shear wave velocity is to some extent costly. this study proposes a novel methodolo...

I derive and analyze an explicit formula for a generalized semblance attribute, which is suitable for velocity analysis of prestack seismic gathers with distinct amplitude trends. While the conventional semblance can be interpreted as squared correlation with a constant, the AB semblance is defined as a correlation with a trend. This measure is particularly attractive for analyzing class II AVO...

The purpose of this study was to conduct a controlled evaluation of the continuous-wave Doppler technique for the estimation of stroke volume changes. Six anesthetized dogs were studied. Aortic blood velocity was recorded from the suprasternal notch by a special continuous-wave Doppler unit. Cardiac output was varied by fluid infusion and exsanguination, and over 300 simultaneous records of aor...

refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...

AVO analysis of seismic data is based on the assumption that transitions in the earth consist of jump discontinuities only. The generalization of this type of transition to a more realistic class of transitions shows a drastic change in observed AVO behavior, especially for the large angles currently attained by increasing cable lengths. We propose a simple approach that accounts for this anoma...

Introduction The SKA site submission process requests an analysis of the tropospheric properties of the candidate sites as they relate to the SKA. The request should be viewed in the context of a radio telescope operating at up to 25 GHz. In particular the RFP requests information on ? Local tropospheric transparency and “microscopic tropospheric stability” ? Diurnal and annual variation of the...

The in situ permeability of a formation is obtained by the inversion of Stoneley wave phase velocity and attenuation, which are evaluated by applying the Extended Prony's method to the array sonic logging data. The Maximum Likelihood inversion is used together with logarithmic parameterization of the permeabilities. Formation shear wave velocity is also inverted for. This process is tested on b...