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...

Background. The contour of the common carotid artery (CCA) blood flow velocity waveform changes with age; CCA flow velocity increases during late systole, and this may contribute to cerebrovascular disease. Late systolic flow velocity augmentation can be quantified using the flow augmentation index (FAIx). We examined hemodynamic correlates of FAIx to gain insight into determinants of CCA flow ...

Love waves are generally less employed than Rayleigh waves in near-surface shear-wave (S-wave) investigations because acquiring S-wave data is not as easy as acquiring P-wave data. The dispersion of Love waves, however, is independent of Poisson’s ratio. This character can be the valuable basis to improve the S-wave velocity imaging. The sensitivity of earth properties to the dispersion curve o...

2014 The aim of this communication is to describe the main results which we have obtained in the past years on the electronic properties of grain boundaries in semiconductors. The study, experimental as well as theoretical, has focused on the main electronic characteristics i.e. density of states, optical cross sections, carrier capture cross sections (and recombination velocity) from which all...

[1] Nicaraguan volcanoes show globally high concentrations of geochemical tracers from dehydration of subducting crust, which may reflect a slab with unusually high amounts of H2O. To test this possibility, we measure seismic velocities at the top of the subducted plate and compare them with predictions for hydrated mafic rocks. Regional seismic P waves for intraslab events at 100–150 km depth ...

The observed deficit of B solar neutrinos may call for an improved standard model of the sun or an expanded standard model of particle physics (e.g., with neutrino masses and mixing). In the former case, contemporary fluid motions and thermal fluctuations in the sun’s core may modify nuclear reaction rates and restore agreement. To test this notion, we propose a search for short–term variations...

background: we sought to assess right ventricular (rv) systolic and diastolic functions via tissue doppler imaging (tdi) in order to discriminate right-to-left (bidirectional) from left-to-right intracardiac shunts. methods: a tissue doppler velocity study via doppler echocardiography was performed in 20 patients with left-to-right shunt (without evidence of significant pulmonary hypertension) ...