Results 301 to 310 of about 306,957 (330)

Reflection coefficients in attenuative anisotropic media

GEOPHYSICS, 2009
Such reservoir rocks as tar sands are characterized by significant attenuation and, in some cases, attenuation anisotropy. Most existing attenuation studies are focused on plane-wave attenuation coefficients, which determine the amplitude decay along the raypath of seismic waves.
Jyoti Behura, Ilya Tsvankin
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Attenuation and reflection coefficient nomogram

Ultrasonics, 1974
Abstract A nomogram is described for the determination of the sound pressure reflection coefficient R and the round-trip loss 2 α L when using the pulse-echo buffer rod technique.
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An Anisotropic Modelling for the Determination of Regional Attenuation Coefficients

Natural Hazards, 1998
The anisotropic attenuation of macroseismic intensity for a seismogenetic zone is dealt with using a new modelling of intensity distribution. The analysis, carried out starting from the intensity maps of the earthquakes of different seismogenetic zones of Central and Southern Italy, allows the determination of the attenuation coefficients for each ...
TERAMO, Antonio, TERMINI, Domenica, STILLITANI E., BOTTARI, Antonio   +3 more
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Diffuse attenuation coefficient profiles

IEEE Transactions on Geoscience and Remote Sensing, 1994
Diffuse attenuation coefficient (k/sub d/, k/sub u/) eigenanalysis, using field data, is performed. Data are partitioned into wavelength, province, season, and up/downwelling k. Resulting eigenvectors and scalar multiples allow a reconstruction of the original k profiles. Parameterizing the scalar multiples, using satellite derived surface k's, k depth
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Frequency variability of modal attenuation coefficients

The Journal of the Acoustical Society of America, 2007
The intrinsic sediment attenuation in adiabatic waveguides affects transmission loss through the modal attenuation coefficients (MACs). For sand-silt bottoms, the non-linear frequency dependence of attenuation in the upper sediment layer significantly affects the frequency variation of the MACs.
William L. Siegmann, William M. Carey, Allan D. Pierce, Wendy Saintval   +3 more
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Measurement of Ultrasonic Attenuation Coefficient of Mud

Advanced Materials Research, 2011
Ultrasonic attenuation coefficient of media phase is an important parameter in process tomography by amplitude method. At normal temperature (25°C), the experiment adopts continuous pulse string with the frequency of 0.5 MHz to measure ultrasonic attenuation coefficient of mud (average particle size about 300µm; water content 17%; mud-sand ratio 1:9 ...
Ming Zhou, Lin Zhang, Fu Qun Shao
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Gamma-Ray Attenuation-Coefficient Measurements

Physical Review A, 1970
Total $\ensuremath{\gamma}$-ray attenuation coefficients have been measured at nine energies in the range of 88 keV to 2.75 MeV for the following elements: Be, C, Mg, Al, S, Ti, Fe, Ni, Cu, Zn, Zr, Nb, Mo, Ag, Sn, La, Gd, Hf, W, Au, Pb, Th, U, and Pu. Radioactive isotopes were used as sources of monoenergetic $\ensuremath{\gamma}$ radiation in a narrow-
A. L. Conner, J. H. McCrary, H. F. Atwater, Elizabeth H. Plassmann   +3 more
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An accurate parametrisation of the X-ray attenuation coefficient

Physics in Medicine & Biology, 1980
A parametrisation starting from the fundamental theory of photon-electron interactions has been devised. In this note the authors report the expression obtained and the accuracy achieved for elements common in tissue and contrast media.
David J. Hawkes, D F Jackson
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Mass attenuation coefficients of β+-particles

Applied Radiation and Isotopes, 1999
Abstract The beta-spectra for the allowed transition and the first forbidden unique transition are calculated with enough accuracy. By applying them to the semiempirical transmission equation of monoenergetic electrons and positrons, we obtained the mass attenuation coefficients of beta-particles.
H.S. Han, H.S. Chai, C.Y. Yi, J.-S Jun
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Unbiased Estimation of Atmosphere Attenuation Coefficient

Electrical Engineering, 2006
According to the passive sensors’ nature, only the azimuth and elevation angles are used for the target state estimation. In some scenarios, additional information like the irradiances generated by the passive sensors must be introduced to improve the estimation process. On the other hand, irradiances are strongly dependent on the atmosphere properties
G. D. Dikic, Z. M. Djurovic
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