نتایج جستجو برای: frequency dependence increases with increasing q0 values. overall
تعداد نتایج: 9710766 فیلتر نتایج به سال:
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...
in this thesis protic and aprotic ammonium-based ionic liquids were synthesized and their surface tensions were measured in the range of 298-373k. the protics are alkyl ammonium-based ils with the carboxylate (formate, acetate, propionate) anion and aprotics are quaternary ammonium-based ils with bis(trifluoromethylsulfonyl)imide anion. capillary rise method was used for surface tension measure...
in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...
during natural gas processing, water in natural gas may cause to hydrates formation in pipelines which may lead to serious damages to process equipments. given the problems raised by present of water in natural gas, glycol solvent uses to remove water.in contact of glycol with gas always an amount of btex and voc absorb along with water, which on glycol recovery process, these substances separa...
in this thesis,spin dependend transport and electron transport through of ng/sg(graphene/ superconductor graphen) are studied in the junction of ng/fgt/sg. due to andreev reflection conductance increases in the presence of superconductor graphene.also, by applying a voltage gate on a superconductor, fermi level shifts and the conductance is independent of ferromagnatic substrate. also, the cond...
applications such as high definition viedeo reproduction, portable computers, wireless, and multimedia demand, and ever-increasing need for ligh-frequency high-resolution and low-power analog-to-digital converters. flash, two-step flash, and pipeline convertors are fast but consume large amount of power and require large area. to overcome these problems, successive approximation converter blo...
drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...
[1] The frequency dependence of Q in Earth’s upper mantle is investigated using the continuous P wave spectra over 0.08 < f < 8.0 Hz. Regional waveform data from 23 events in the Pacific slab recorded on broadband stations in western Japan were used to create spectral ratio estimates of P waves which sample a subducting slab and mantle wedge. We assumed the power-law model Q( f ) = Q0( f/f0) a ...
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 ...
the effect of four types of shortening including a commercially vegetable oil (as control), palm olein (po), palm stearin (ps), and a blend of the latter two oils with rapeseed oil (bf) on the rheological properties of cookie dough was determined by using dynamic oscillatory measurement testing. all of the obtained dough treatments showed weak liquid viscoelastic behavior. their storage (g ) an...
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