Frequency-dependent attenuation (1/Q) should be used as a seismic attribute to improve the accuracy of methods and imaging subsurface. In rocks, 1/Q is highly sensitive presence saturating fluids. Thus, could crucial monitor volcanic hydrothermal domains explore hydrocarbon water reservoirs. The experimental determination teleseismic (i.e., for frequencies < 100 Hz) challenging, conseque...

The bioultrasonic spectroscopy system was employed for measurements of velocity and attenuation coefficient of glucose solutions in the VHF/UHF range. The relation between the slope of the square of velocity and the relaxation parameters, and the relation between the frequency exponent on attenuation coefficient and the relaxation parameters are investigated. In order to carry out numerical cal...

The theoretical part of the research methodology is developed according to scheme subsidence points on earth's surface relative projection face. curve trajectory divided by characteristic at different stages surface. Such include: beginning displacement surface, active stage displacement, end and attenuation processes According goal design scheme, basis experimental data, we determined paramete...

BACKGROUND Functional studies indicate that sympathetic efferents are located in the superficial subepicardium and vagal efferents are located in the subendocardium. It is possible that electrical shocks applied directly to the heart might affect the function of these autonomic nerves. METHODS AND RESULTS Low- (< or = 1 J), medium- (6 to 16 J), or high- (30 to 35 J) energy truncated monophasi...

it is well known that the matrix exponential function has practical applications in engineering and applied sciences. in this paper, we present some new explicit identities to the exponential functions of a special class of matrices that are known as central-symmetric $x$-form. for instance, $e^{mathbf{a}t}$, $t^{mathbf{a}}$ and $a^{mathbf{a}t}$ will be evaluated by the new formulas in this par...

Seismic attenuation occurs during seismic wave propagation in a viscous medium, which will result poor image of subsurface structures. The compensation by directly amplifying the extrapolated wavefields may suffer from numerical instability because exponential for wavefields. To alleviate this issue, we have developed stabilized frequency-domain Q-compensated reverse time migration (FQ-RTM). In...

in this paper we present a method to perform flood frequency analysis (ffa) when the assumption of stationary is not important (or not valid). a wavelet transform model is developed to ffa. a full series is applied to ffa using two different wavelet functions, and then a combined method is investigated. in the combined method, all discharge data which were less than the lowest value of annual m...

This work develops a second-order approximation (SOA) model and three-dimensional (3D) finite element (FE) to calculate scattering-induced attenuation for elastic wave propagation in polycrystals with elongated grains of arbitrary crystal symmetry. The SOA accounts some degree multiple scattering, whereas the 3D FE includes all scattering possibilities. incorporates accurate geometric two-point...