in many seismological applications, the earth is considered as a perfectly elastic, homogeneous, and isotropic body. although this assumption is approximately valid, it is known that seismic waves pass through the real earth that is anelastic, inhomogeneous and anisotropic.  we consider four processes that can reduce wave amplitude, i.e.: geometrical spreading, scattering, multi-pathing, and an...

The S parameters, attenuation characteristics and group delay characteristics of the Teflon tube have been analyzed in the paper. Firstly, the S parameters of metal and polymer tube with the same structure are compared. Then the transmission properties of the simple terahertz Teflon tubes and terahertz Teflon tubes which are coated metal film by three different ways are simulated, and the advan...

An analytical overview of research involving EM waves attenuation by vegetation canopies in the frequency range 100...10000 MHz is given. Brief descriptions of objects of investigation and typical biometric features are presented. The models of vegetation as a continuous medium and as a collection of scatterers are considered. Dielectric properties of vegetative material are discussed. The rela...

Aims Early reports of micro computed tomography (micro CT) of urinary stones showed non-overlapping ranges of x-ray attenuation values for most minerals. However, extended work in our laboratory has shown that size of stone fragments and scanning parameters can each influence the apparent x-ray attenuation value of minerals. The purpose of the present study was to test the correlation of minera...

seismic waves when crossing the earth in heterogeneous and anisotropic environments, having interaction. recognizing the impact of these factors on the seismograms help us to find out more information about interior of the earth. coda waves are the main reason for the random heterogeneities in earth. local earthquakes in the northeast region of iran with epicentral distance less than 200 km is ...

Background: High density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. Over the past eight years, some efficient galena-based concrete samples for shielding X or gamma rays was produced. The goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. Materials an...

We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. separate source spectra site terms determine intrinsic attenuation scattering strength shear waves 3 Hz 200 frequency range using radiative transfer based synthetic envelopes. Displacement yield scaling relations with a general deviation from self-sim...