Selection of Single Scattering from Multiple Scattering Systems by 3D Cross-Correlation. 2. Concentrated Polymer Solutions

2002 ◽  
Vol 35 (5) ◽  
pp. 1877-1886 ◽  
Author(s):  
L. B. Aberle ◽  
M. Kleemeier ◽  
O.-D. Hennemann ◽  
W. Burchard
Keyword(s):  
Multiple Scattering ◽  
Cross Correlation ◽  
Polymer Solutions ◽  
Single Scattering ◽  
Scattering Systems ◽  
Selection Of

Background Fitting in the Low-Loss Region of Electron Energy Loss Spectra

1990 ◽  
Vol 48 (2) ◽  
pp. 56-57
Author(s):  
C P Scott ◽  
A J Craven ◽  
C J Gilmore ◽  
A W Bowen
Keyword(s):  
Energy Loss ◽  
Multiple Scattering ◽  
Simple Form ◽  
Single Scattering ◽  
Low Loss ◽  
Characteristic Energy ◽  
Normal Method ◽  
Fitting In ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

The normal method of background subtraction in quantitative EELS analysis involves fitting an expression of the form I=AE-r to an energy window preceding the edge of interest; E is energy loss, A and r are fitting parameters. The calculated fit is then extrapolated under the edge, allowing the required signal to be extracted. In the case where the characteristic energy loss is small (E < 100eV), the background does not approximate to this simple form. One cause of this is multiple scattering. Even if the effects of multiple scattering are removed by deconvolution, it is not clear that the background from the recovered single scattering distribution follows this simple form, and, in any case, deconvolution can introduce artefacts.The above difficulties are particularly severe in the case of Al-Li alloys, where the Li K edge at ~52eV overlaps the Al L2,3 edge at ~72eV, and sharp plasmon peaks occur at intervals of ~15eV in the low loss region. An alternative background fitting technique, based on the work of Zanchi et al, has been tested on spectra taken from pure Al films, with a view to extending the analysis to Al-Li alloys.

scholarly journals Cramér-Rao Bound Study of Multiple Scattering Effects in Target Separation Estimation

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Edwin A. Marengo ◽  
Paul Berestesky
Keyword(s):  
Multiple Scattering ◽  
Born Approximation ◽  
Single Scattering ◽  
Scattering Data ◽  
Approximation Model ◽  
Scattering Parameters ◽  
Helmholtz Operator ◽  
Scattering Effects ◽  
Cramer Rao Bound ◽  
Multiple Scattering Effects

The information about the distance of separation between two-point targets that is contained in scattering data is explored in the context of the scalar Helmholtz operator via the Fisher information and associated Cramér-Rao bound (CRB) relevant to unbiased target separation estimation. The CRB results are obtained for the exact multiple scattering model and, for reference, also for the single scattering or Born approximation model applicable to weak scatterers. The effects of the sensing configuration and the scattering parameters in target separation estimation are analyzed. Conditions under which the targets' separation cannot be estimated are discussed for both models. Conditions for multiple scattering to be useful or detrimental to target separation estimation are discussed and illustrated.

scholarly journals Investigation of the liquid density using Gamma scattering technique

2017 ◽  
Vol 1 (T1) ◽  
pp. 106-113
Author(s):  
Kien Thach Trung Vo ◽  
Tam Duc Hoang ◽  
Nguyen Hoang Vo ◽  
Chuong Dinh Huynh ◽  
Thanh Thien Tran ◽  
...  
Keyword(s):  
Multiple Scattering ◽  
Density Measurement ◽  
Single Scattering ◽  
Photon Beam ◽  
Scattered Photon ◽  
Liquid Density ◽  
Scattering Angle ◽  
Testing Sample ◽  
Scattering Technique

In this work, a gamma scattering technique using 137Cs (5mCi) source with the NaI(Tl) detector is arranged to record the scattered photon beam at scattering angle of 1200 for investigating the liquid density. We used standard liquid such as water, H2SO4, HCl, glycerol, HNO3, ethanol and A92 petrol to fit the single scattering peak, multiple scattering, and total counts versus standard liquid densities. The interpolating of the single scattering peak, multiple scattering, and total counts of the testing sample at scattering angle of 1200 is 0.702 g.cm-3, 0.783 g.cm-3, and 0.747 g.cm-3, respectively. The discrepancy of the experiment and true testing density is about 8 %, 3 %, and 2 %, respectively. The result shows that multiple scattering or total counts can be used to propose the density measurement.

scholarly journals The Multiple Scattering of Electrons and Positrons

1954 ◽  
Vol 7 (2) ◽  
pp. 217 ◽  
Author(s):  
CBO Mohr ◽  
LJ Tassie
Keyword(s):  
Angular Distribution ◽  
Multiple Scattering ◽  
Born Approximation ◽  
Single Scattering ◽  
Mean Square ◽  
Wkb Method ◽  
Electrons And Positrons

The angular distribution of the single scattering of 33, 121, and 1065 keV electrons at small angles in gold is calculated and compared with the distributions given by the Born approximation and by the WKB method as used by Moli�re. The single scattering distribution for 1065 keV electrons is integrated numerically to give mean square angles of multiple scattering, and these are compared with the values given by the various multiple scattering theories.

Crosscorrelation migration of microseismic source locations with hybrid imaging condition

Geophysics ◽  
2021 ◽  
pp. 1-49
Author(s):  
Shaojiang Wu ◽  
Yibo Wang ◽  
Fei Xie ◽  
Xu Chang
Keyword(s):  
Cross Correlation ◽  
Hybrid Imaging ◽  
Hydraulic Fractures ◽  
Imaging Condition ◽  
Time Scanning ◽  
Comparison Results ◽  
Excitation Time ◽  
Seismic Location ◽  
Location Methods ◽  
Selection Of

Locating microseismic sources is critical to monitor the hydraulic fractures that occur during fluid extraction/injection in unconventional oil or gas exploration. Waveform-based seismic location methods can reliably and automatically image weak microseismic source locations without phase picking. Among them, the cross-correlation migration (CCM) method can avoid excitation time scanning by generating virtual gathers. We propose a CCM location method based on the hybrid imaging condition (HIC). There are four main steps in the implementation of this method: 1) selection of receivers with good azimuthal coverage; 2) generation of virtual gathers by correlating the reference receiver with the rest of the receivers; 3) summation of back-projections in the virtual gathers; and 4) multiplication of all summations. The CCM-HIC method was tested on synthetic and field datasets, and the results were compared with those obtained by conventional summation imaging condition (SIC) and multiplication imaging condition (MIC). The comparison results demonstrate that the CCM-HIC is sufficiently robust to obtain better stability and higher spatial resolution image of source location, despite the presence of strong noise.

Multiple scattering of plane harmonic elastic waves in an infinite solid by an arbitrary configuration of obstacles

1969 ◽  
Vol 66 (2) ◽  
pp. 469-480 ◽  
Author(s):  
P. J. Barratt
Keyword(s):  
Scattering Amplitudes ◽  
Integral Equations ◽  
Multiple Scattering ◽  
Elastic Waves ◽  
Iterative Procedure ◽  
Elastic Solid ◽  
Single Scattering ◽  
Far Field ◽  
Rigid Spheres ◽  
Arbitrary Configuration

AbstractThe multiple scattering of plane harmonic P and S waves in an infinite elastic solid by arbitrary configurations of obstacles is considered. Integral equations relating the far-field multiple scattering amplitudes to the corresponding single scattering functions are obtained and asymptotic solutions are found by an iterative procedure. The scattering of a plane harmonic P wave by two identical rigid spheres is investigated.

A note on the enhancement of J values in optically thick scattering atmospheres

1991 ◽  
Vol 69 (8-9) ◽  
pp. 1166-1174 ◽  
Author(s):  
Jacek W. Kaminski ◽  
John C. McConnell
Keyword(s):  
Multiple Scattering ◽  
Rayleigh Scattering ◽  
Large Fraction ◽  
Coherent Scattering ◽  
Single Scattering ◽  
Average Density ◽  
Infinite Medium ◽  
Scattering Medium ◽  
Surface Reflection ◽  
Thick Medium

In a planetary atmosphere the J value is determined by the angular-averaged radiance, or the average density of photons in an element of volume. The average density may be enhanced by multiple scattering of photons in a conservative, or near-conservative scattering atmosphere. We show that in a conservative semi-infinite medium this enhancement will be a factor of 5, for optical depths greater than about 20 for coherent scattering. We investigate the modification of the J values owing to multiple scattering in an optically thick medium of various optical depths, various single-scattering albedos of the scattering medium, and a range of surface albedos. We have applied the results to the calculation of J values in clouds in the terrestrial atmosphere and in the Rayleigh-scattering atmosphere of Uranus. We note that J values in a realistic atmosphere may be enhanced by as much as a factor of 5 throughout a large fraction of the atmosphere over those calculated without multiple scattering and surface reflection.

Influence of single scattering and multiple scattering on backscattered Mueller matrix in turbid media

2009 ◽  
Vol 7 (1) ◽  
pp. 64-66 ◽  
Author(s):  
徐兰青 Lanqing Xu ◽  
李晖 Hui Li ◽  
郑勇平 Yongping Zheng
Keyword(s):  
Multiple Scattering ◽  
Single Scattering ◽  
Mueller Matrix ◽  
Turbid Media
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