Results 251 to 260 of about 317,605 (301)

Attenuation Coefficient Estimation of Normal Placentas

Ultrasound in Medicine & Biology, 2019
Attenuation coefficient estimation has the potential to be a useful tool for placental tissue characterization. A current challenge is the presence of inhomogeneities in biological tissue that result in a large variance in the attenuation coefficient estimate (ACE), restricting its clinical utility. In this work, we propose a new Attenuation Estimation
Farah Deeba, Manyou Ma, Mehran Pesteie, Jefferson Terry, Denise Pugash, Jennifer A. Hutcheon, Chantal Mayer, Septimiu Salcudean, Robert Rohling   +8 more
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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, H. F. Atwater, Elizabeth H. Plassmann, J. H. McCrary   +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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Gamma-Ray Attenuation Coefficient Measurements

Physical Review A, 1973
In an earlier paper, published by the author elsewhere, it was shown that for 661.6-keV gamma rays the measurements of gamma -ray attenuation coefficicnts would greatly improve if one uses the counting sequence of Conner et al. together with a new criterion mu t < 1, where mu is the gamma -ray attenuation coefficient and t is the thickness of the ...
S. Gopal, B. Sanjeevaiah
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Investigation of photon attenuation coefficients for marble

Journal of Radiological Protection, 2005
The total linear attenuation coefficients micro (cm(-1)) have been obtained using the XCOM program at photon energies of 1 keV to 1 GeV for six different natural marbles produced in different places in Turkey. The individual contribution of photon interaction processes to the total linear attenuation coefficients for marble has been investigated.
Kilincarslan, S, Basyigit, Celalettin, Akkurt, I, AKKURT, A   +3 more
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Model Diffuse Attenuation Coefficient Profiles

[Proceedings] IGARSS '92 International Geoscience and Remote Sensing Symposium, 2005
Abstract : Light transport through water is controlled by the properties of dissolved substances, particulate matter, and water itself. The rate at which the light field decays can be measured by optical instrumentation and parameterized by the apparent optical property of the water, the diffuse attenuation coefficient, k.
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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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Linear attenuation coefficients for compensator based imrt

Australasian Physics & Engineering Sciences in Medicine, 2007
With rapid technological improvements in computer driven 3-D radiotherapy treatment planning systems (RTPS) the use of compensating filters for intensity modulated radiation therapy (IMRT) will dramatically increase the ease of treatment. The procedure for commissioning .decimal (Sanford, Florida) compensators involved the measurement of the effective ...
T, Bartrum, M, Bailey, V, Nelson, M, Grace   +3 more
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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.
Wendy Saintval, William L. Siegmann, William M. Carey, Allan D. Pierce   +3 more
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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.
C.Y. Yi, H.S. Han, J.S. Jun, H.S. Chai
openaire   +1 more source