WE-C-L100J-02: Determination of Pixel-Value to X-Ray Path-Length Conversion Factor From Single Angiograms

2007 ◽  
Vol 34 (6Part20) ◽  
pp. 2585-2585
Author(s):  
E Erdemir ◽  
K Hoffmann ◽  
A Gopal
Keyword(s):  
Path Length ◽  
Conversion Factor ◽  
X Ray ◽  
Pixel Value ◽  
Ray Path

X-Ray Absorption-Edge Determination of Cobalt in Complex Mixtures*

1961 ◽  
Vol 5 ◽  
pp. 379-388
Author(s):  
E.A. Hakkila ◽  
G.R. Waterbury
Keyword(s):  
Nitric Acid ◽  
Absorption Edge ◽  
Path Length ◽  
Construction Materials ◽  
X Ray ◽  
Relative Standard ◽  
Standard Deviations ◽  
Low X ◽  
X Ray Absorption

AbstractThe application of the X-ray absorption-edge technique was extended to the determination of cobalt in aqueous and alcoholic solutions containing a wide variety of impurity elements. In the procedure developed, secondary radiation from a 50% copper-nickel alloy is passed through an absorption cell filled alternately with the solvent and the sample solution. The transmitted Intensities of the Kα lines for copper and nickel are measured, and the concentration of cobalt is determined using accepted absorption principles. The K absorption edge for cobalt occurs at 1.604 A, restricting cell construction materials and solvents to those containing light elements with low X-ray absorption characteristics and also limiting the path length of the cell.Cells of 0.16- and 0.34-cm path length were used in the analysis of aqueous and alcoholic solutions, respectively. With the 0.16-cm path-length cell, relative standard deviations of 4.6 to 0.5% were obtained for cobalt concentrations ranging from 1.00 to 10.00 mg/ml for known aqueous solutions that contain various known concentrations of nitric acid. With the longer path-length cell, relative standard deviations from 1.8 to 0.46% were obtained for cobalt concentrations in the same range in known alcoholic solutions containing various known concentrations of nitric acid. The standard deviation of determining the blank is 0.043 mg of cobalt per milliliter for the 0.16-cm cell and 0.016 mg of cobalt per milliliter for the longer cell.A Norelco X-ray spectrograph with a three-position head was used in these analyses. Less than 5 min is required to convert this instrument from normal fluorescence operation to absorption-edge analysis. Approximately 15 to 20 analyses can be performed daily.

scholarly journals Unfolding Method with X-ray Path Length-Dependant Response Functions for Computed Tomography Using X-ray Energy Information

2010 ◽  
Vol 47 (11) ◽  
pp. 1075-1082 ◽  
Author(s):  
Ryo IMAMURA ◽  
Kenta MIKAMI ◽  
Yuko MINAMI ◽  
Ikuo KANNO ◽  
Masahiko OHTAKA ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Path Length ◽  
Response Functions ◽  
X Ray ◽  
Ray Path ◽  
Unfolding Method ◽  
Energy Information

Modified hydrothermal diamond anvil cells for XAFS analyses of elements with low energy absorption edges in aqueous solutions at sub- and supercritical conditions

2000 ◽  
Vol 215 (12) ◽  
Author(s):  
W.A. Bassett ◽  
A.J. Anderson ◽  
R.A. Mayanovic ◽  
I.-M. Chou
Keyword(s):  
Aqueous Solutions ◽  
Path Length ◽  
Elevated Temperatures ◽  
Hydrothermal Systems ◽  
X Rays ◽  
Transition Elements ◽  
X Ray ◽  
Diamond Anvils ◽  
Diamond Anvil ◽  
Ray Path

Two modifications of the hydrothermal diamond anvil cell (HDAC) have been made, the first for transmission XAFS (X-ray absorption fine structure) analyses and the second for fluorescence XAFS analyses of elements with low absorption edge energies. In the first modification, laser-drilled holes in the diamond anvils reduce the X-ray path-length in diamond to 300 µm in order to minimize the attenuation of X-rays due to absorption and scatter. In the second modification, laser-machined cup and grooves in one of the diamond anvil faces reduces the X-ray path-length in diamond to 160 µm and permits a 90° take-off angle. Both modifications can be used to obtain XAFS spectra on aqueous solutions of first-row transition elements as well as rare earth elements at elevated temperatures and pressures. The second modification is capable of measurements on solutions of concentrations in parts per million (ppm) range. These techniques are being used for carrying out experimental measurements valuable in the interpretation of fluid inclusions in minerals found in ore-forming hydrothermal systems as well as other important lithospheric processes involving water.

Helium Path Diffractometry and its Application to Determination of Retained Austenite and Macrostress in Steel

1962 ◽  
Vol 6 ◽  
pp. 85-90
Author(s):  
Robert A. McCune
Keyword(s):  
Retained Austenite ◽  
Intensity Increase ◽  
X Rays ◽  
X Ray ◽  
Long Wavelength ◽  
Gauge Block ◽  
Background Ratio ◽  
Ray Path

AbstractThe helium X-ray path has long been used, in spectrography to increase the intensity of the long-wavelength X-rays. The same principle has been applied to diflractometry. Up to threefold intensity increase is observed with chromium Ka radiation with very little increase In background. The peak to background ratio, therefore, is Improved by almost the same factor as the increase in intensity. Application of the technique is illustrated by analysis of gauge block steel for retained austcnite and macrostress.

Single-Energy Material Decomposition Using X-Ray Path Length Estimation

2012 ◽  
Vol 36 (6) ◽  
pp. 768-777 ◽  
Author(s):  
Benedek Janos Kis ◽  
Zsolt Sarnyai ◽  
Róbert Kákonyi ◽  
Miklós Erdélyi ◽  
Gábor Szabó
Keyword(s):  
Path Length ◽  
Material Decomposition ◽  
X Ray ◽  
Length Estimation ◽  
Energy Material ◽  
Ray Path

DETERMINATION OF THE DISINTEGRATION RATE OF NUCLIDES DECAYING BY ELECTRON CAPTURE

1961 ◽  
Vol 39 (3) ◽  
pp. 717-728 ◽  
Author(s):  
J. R. S. Drouin ◽  
L. Yaffe
Keyword(s):  
Electron Capture ◽  
Energy Resolution ◽  
Proportional Counter ◽  
Path Length ◽  
Average Path Length ◽  
Gas Pressure ◽  
Disintegration Rate ◽  
X Ray

In an attempt to determine disintegration rates of nuclides decaying by electron capture, various properties of a 2π proportional counter spectrometer were studied. These included gas multiplication, energy resolution, and energy linearity. The result of varying anode size, gas pressure, and nature of the gas was also investigated. An experimentally determined average path length for characteristic X-ray energies between 4 and 24 kev was found.

The Direct Determination of Vanadium and Nickel in Crude Oils by X-Ray Fluorescence

1959 ◽  
Vol 3 ◽  
pp. 131-137
Author(s):  
Victoria R. Lopp ◽  
C. G. Claypool
Keyword(s):  
Standard Deviation ◽  
Direct Determination ◽  
Optical Emission ◽  
Crude Oils ◽  
Internal Standards ◽  
X Ray ◽  
Trapped Air ◽  
Sample Chamber ◽  
Ray Path

AbstractA rapid method has been developed for the determination of vanadium and nickel in crude oils in concentrations above 5 ppm. Duplicate analyses for both nickel and vanadium require only one hour, and excellent precision is obtained. At a concentration level of 100 ppm of vanadium, the standard deviation is 3.1 ppm, and at a level of 30 ppm of nickel, the standard deviation is 1.6. The results are comparable to those obtained by spectrophotometric and optical emission spectrographic analysis.Conversion of the crude oils to greases by the addition of aluminum stéarate minimizes the usual difficulties of handling liquid samples in the conventional-geometry fluorescent X-ray spectrometer. Scattered tungsten emission lines from theX-ray tube serve as internal standards to correct for instrumental and matrix variations.A new sample tray that permits the insertion of four samples into the instrument at a time has been constructed. Each sample can be moved into position for analysis without opening the sample chamber, making it necessary to waitfor the helium to sweep the trapped air from the X-ray path only once for each four samples.

scholarly journals On the optical analysis of the ray path-lengths in the diffraction of femtosecond XUV and soft X-ray pulses

2000 ◽  
Vol 18 (3) ◽  
pp. 529-534 ◽  
Author(s):  
P. VILLORESI
Keyword(s):  
Path Length ◽  
Optical Analysis ◽  
Spectral Filtering ◽  
High Order Harmonic Generation ◽  
X Ray ◽  
High Order Harmonic ◽  
The Difference ◽  
Path Lengths ◽  
Ray Path ◽  
Selection Of

During the diffraction of a femtosecond pulse with a grating, apart spectral filtering, there occurs a time stretching due to the difference in the path length among the rays diffracted, even of equal wavelength. The reason resides in the action of the grating: to depart from the behavior of the mirror, that is, α = β, and to direct the rays in directions whose paths are groove-by-groove different of mλ. The compensation of this broadening is studied in the following by using a pair of grating in a particular mounting. The configuration is studied for the application in the selection of one single laser harmonics in the framework of high order harmonic generation processes.

Simple Two Crystal Spectrometer and its Application to X-Ray Spectrochemical Analysis

1968 ◽  
Vol 12 ◽  
pp. 518-533 ◽  
Author(s):  
Y. Gohshi
Keyword(s):  
Wavelength Region ◽  
Resolving Power ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Long Wavelength ◽  
Wide Wavelength Range ◽  
Window Region ◽  
Fine Structures ◽  
Ray Path

AbstractA simple two-crystal spectrometer was constructed, making use of a commercial one-crystal spectrometer. A detector attached to a 2θ-arm has been replaced by a second crystal. After adjustment, the second crystal is fixed to the 2θ-arm. The detector is placed at an appropriate position apart from the 2θ-arm. The spectrometer is operated as if it were a one-crystal spectrometer. The dispersion of the spectrometer in this mode of operation is the sum of those of the first and second crystals. Ge(220) crystals gave the best resolution which was about 3-3 eV fwhm for Cu Kα1. The strongest Intensity was observed using etched LIF crystals. The intensity was about 1/4 of that of a one-crystal spectrometer and the resolution was about 9.5 eV fwhm for Cu Kα1. The spectrometer was applied to the determination of hafnium in zirconium and sircaloy. The Zr Kα 2nd order line, which coincides with the Hf Lα1 line, was completely eliminated by successive reflections by Ge(111) crystals owing to the extinction rule and the high resolving power. The detection limit was about 7 ppm of hafnium. Another example is the separation of the As Kα2 line from the Pb Lα1 line. Arsenic in low alloy steel was determined without the correction for the well known Interference of lead. The very common interference of Cr Kβ on Mn Kα was also eliminated completely by this spectrometer. Though the spectrometer is not very suitable for a wide wavelength range spectroscopic measurement, owing to its narrow window region (about ±1°), the chemical effects on Kg spectra of sulfur in various compounds were investigated. Fine structures were found In the sulfur Kβ spectra of several thiocyanates and elemental sulfur. To observe long wavelength region spectra, the X-ray path of the spectrometer was modified to a hybrid path (vacuum and helium).

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

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