seismic waves travelling through inelastic media are attenuated by the conversion of elastic energy into heat. upon being attenuated, the travelling wave changes: amplitude is reduced, travelling waveform is modified due to high-frequency content absorption, and phase is delayed. attenuation is usually quantified through the quality factor q: the ratio between the energy stored and lost in each...

S U M M A R Y We study analytically and numerically effects of attenuation on cross-correlation functions of ambient noise in a 2-D model with different attenuation constants between and outside a pair of stations. The attenuation is accounted for by quality factor Q(ω) and complex phase velocity. The analytical results are derived for isotropic far-field source distribution assuming the Fresne...

water quality prediction is a valuable tool for pollutant control in aquatic environments. a river system is selected and one-dimensional flow is assumed for the simulation of pollutant transport in this paper. advective and diffusive terms of transport equation are considered separately. different functions of advective transport are proposed and applied for a specified velocity on the discret...

development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

It is well-known that in the disordered harmonic chain, heat conduction is subballistic and the thermal conductivity (κ) scales asymptotically as lim(L--> ∞) κ ∝ L(0.5) where L is the chain length. However, using the nonequilibrium Green's function (NEGF) method and analytical modelling, we show that there exists a critical crossover length scale (LC) below which ballistic heat conduction (κ ∝...

[1] We examine waveforms and data used to construct coda magnitude in southern California to estimate the spatial variation of coda Q and its dependence on frequency. Our analysis combined with independent borehole data suggests that coda is mainly generated by multiple scattering in the upper few kilometers of the crust where large impedance contrasts occur because of surface layering or fract...

amplitudes of seismic waves decrease with distance according to anelastic properties of the earth and geometrical spreading. the attenuation of ground-motion amplitudes in the frequency domain is an important problem in engineering seismology. it is of particular practical interest in the regions such as zagros (iran). the zagros fold- thrust belt, as a part of alpine- himalayan orogenic belt i...

in this paper, global uniform exponential stability of perturbed dynamical systemsis studied by using lyapunov techniques. the system presents a perturbation term which isbounded by an integrable function with the assumption that the nominal system is globallyuniformly exponentially stable. some examples in dimensional two are given to illustrate theapplicability of the main results.