Characterization and Correction of Geometric Errors Induced by Thermal Drift in CT Measurements

The occurrence of thermal drift in industrial computed tomography (CT) systems has been reported as a significant source of error on geometrical evaluations. During CT-scans, heating inside the cabinet and varying environmental conditions may affect the position of the focal spot and distort the manipulator system, leading to relative displacement of X-ray projections and distortions in the reconstructed 3D image. This paper presents an experimental investigation on influence of the thermal effects on dimensional CT measurements. A correction method based on the manipulation of the projections was developed and evaluated. The method consists in repeating the acquisition of first projection at the end of the scan and calculating the displacement vector between these projections. The remaining projections are then corrected proportionally to this displacement. The results showed a significant reduction of the roundness deviation values measured on a precision sphere after the correction.

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X-ray analysis of mechanical and thermal effects induced by femtosecond laser treatment of aluminum single crystals

Applied Surface Science ◽

10.1016/j.apsusc.2005.07.160 ◽

2006 ◽

Vol 252 (13) ◽

pp. 4691-4695 ◽

Cited By ~ 15

Author(s):

S. Valette ◽

R. Le Harzic ◽

E. Audouard ◽

N. Huot ◽

R. Fillit ◽

...

Keyword(s):

Femtosecond Laser ◽

Single Crystals ◽

Laser Treatment ◽

Thermal Effects ◽

X Ray

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Baseline correction method based on improved adaptive iteratively reweighted penalized least squares for the X-ray fluorescence spectrum

Applied Optics ◽

10.1364/ao.425473 ◽

2021 ◽

Author(s):

Jiang Xiaoyu ◽

Li Fusheng ◽

Wang Qingya ◽

Luo Jie ◽

Hao Jun ◽

...

Keyword(s):

Least Squares ◽

Fluorescence Spectrum ◽

Correction Method ◽

Baseline Correction ◽

Penalized Least Squares ◽

X Ray

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Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

Modern Physics Letters B ◽

10.1142/s0217984921504078 ◽

2021 ◽

pp. 2150407

Author(s):

S. I. Ibrahimova

Keyword(s):

Crystal Structure ◽

Differential Scanning Calorimetry ◽

Thermal Properties ◽

Thermal Effects ◽

Room Temperature ◽

Structural Studies ◽

X Ray Diffraction ◽

Hexagonal Symmetry ◽

Scanning Calorimetry ◽

X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

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X-Ray Fluorescence Analysis of Nonhomogeneous Materials by Δμ-Correction Method

Advances in X-ray Analysis ◽

10.1154/s0376030800012945 ◽

1991 ◽

Vol 35 (B) ◽

pp. 749-754

Author(s):

V. I. Karmanov ◽

V. V. Zagorodny

Keyword(s):

Reference Sample ◽

Fluorescence Analysis ◽

Correction Method ◽

Electrode Coating ◽

X Ray ◽

Fundamental Parameters ◽

Sample Composition ◽

Combined Use ◽

Welding Electrode ◽

Excitation Conditions

AbstractThe fundamental parameters method (FPM) enables one to determine with high accuracy the chemical composition of homogeneous samples, having only one reference sample. However, the reference sample composition should be similar to that of the samples analyzed.The x-ray fluorescence analysis of multicomponent heterogeneous materials (ores, minerals, their mixtures, welding electrode coating mixtures, fluxes, etc.) is made by the Δμ-correction method based on the combined use of the fundamental and empirical correlations maintaining all the advantages of the FPM. Sample composition is calculated on the basis of the element intensities measured in the sample and in the reference specimen and is corrected for the disturbing effect of excitation conditions and heterogeneity as well as the calculated values of one of the fundamental parameters (μ1). At the preliminary stage of calibration, the coefficients are determined using regression and the absolute fundamental expression for the element fluorescence intensity.

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High-temperature structural change and microtexture formation of sillimanite and its phase relation with mullite

American Mineralogist ◽

10.2138/am-2019-6732 ◽

2019 ◽

Vol 104 (7) ◽

pp. 1051-1061

Author(s):

Yohei Igami ◽

Shugo Ohi ◽

Tetsu Kogiso ◽

Noboru Furukawa ◽

Akira Miyake

Keyword(s):

Axial Length ◽

Phase Relation ◽

Displacement Vector ◽

Treatment Temperature ◽

X Ray ◽

Cell Parameters ◽

Double Peaks ◽

Heat Treated ◽

Xrd Patterns ◽

Anti Phase Boundary

Abstract Synchrotron powder X-ray diffraction (XRD) experiments and transmission electron microscopy (TEM) observations of heat-treated sillimanite at various pressures were conducted to clarify the detailed phase relation between sillimanite and mullite. Under TEM, heat-treated sillimanite frequently showed anti-phase boundary (APB)-like textures with a displacement vector of ½[001]sil. Additional scanning TEM energy-dispersive X-ray spectroscopy analysis of regions with APB-like texture showed that they were clearly enriched in Al and accompanied by very fine, Si-rich glass inclusions, which indicates that the APB-like textures are composed of fine mullite. Moreover, synchrotron XRD patterns of these samples clearly showed double peaks of newly formed mullite and remnant sillimanite, indicating that the compositional transformation from sillimanite to mullite and glass is discontinuous. We separately determined the cell parameters of the sillimanite and mullite from the XRD pattern and found that the b axial length of the sillimanite increased with the treatment temperature, reflecting disordering of tetrahedral Al and Si in the sillimanite. In contrast, the positions of the deconvoluted mullite peaks indicated that the a axial length of mullite decreased as experimental pressure increased, owing to enrichment of the Si component. By projecting the cell parameters onto the a–b axial plane, the detailed changes in the crystallographic state of the sillimanite and mullite could be easily and comprehensively identified. On the basis of our results, we propose a new P-T diagram for the Al2SiO5 system that shows the transformation boundary between sillimanite and mullite + SiO2-rich melt and the contour of the Al/Si order parameter of sillimanite.

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High-Temperature Modifications of Thorium Dicarbide

Advances in X-ray Analysis ◽

10.1154/s0376030800002998 ◽

1964 ◽

Vol 8 ◽

pp. 78-85 ◽

Cited By ~ 1

Author(s):

P. K. Gantzel ◽

S. Langer ◽

N. L. Baldwin ◽

F. L. Kester

Keyword(s):

Thermal Analysis ◽

Differential Thermal Analysis ◽

High Temperature ◽

Thermal Effects ◽

Room Temperature ◽

Thermal Analyses ◽

Tetragonal Modification ◽

X Ray ◽

Space Groups ◽

Heating And Cooling

AbstractThermal analyses of samples of thorium dicarbide in equilibrium with graphite show arrests which indicate phase transitions at 1427 ± 21°C arid 1481 ± 28°C. These thermal effects have been observed on heating and cooling both in standard thermal analysis and in differential thermal analysis using graphite as a reference material. The microstructure of thorium dicarbide samples shows the characteristic “herringbone” pattern of a material which has undergone a martensitic-type transition.A high-temperature X-ray investigation has revealed that the observed thermal arrests correspond to erystallographic transformations. The monodinic modification found at room temperature is stable to 1427°C, at which temperature a tetragonal modification with a0 = 4.235 ± 0.002Å and c0 = 5.408 ± 0.002Å is formed. At 1481°C, the tetragonal is transformed to cubic with a0 = 5.809 ± 0.002 Å. The best agreement between observed and calculated intensities has been obtained with C-C units of 1.5-Å assumed bond length in space groups P42/mmc and Pa3 for the tetragonal and cubic modifications, respectively.

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A method for determining the CEC and chemical composition of clays via XRF

Clay Minerals ◽

10.1180/0009855064130214 ◽

2006 ◽

Vol 41 (3) ◽

pp. 717-725 ◽

Cited By ~ 3

Author(s):

S. Battaglia ◽

L. Leoni ◽

F. Sartori

Keyword(s):

Matrix Effects ◽

Fluorescence Analysis ◽

Correction Method ◽

Exchange Capacity ◽

New Method ◽

Chemical Compositions ◽

Wet Chemistry ◽

X Ray ◽

Accuracy And Precision ◽

Source Clays

AbstractA new method for determining the cation exchange capacity (CEC) of clays is proposed. The method is based on X-ray fluorescence analysis of natural and Ba-exchanged clays following the analytical procedure suggested by Franzini et al. (1975). This procedure, which utilizes powder pellets and is based on a full matrix correction method, is frequently applied in Earth Sciences laboratories for the routine analysis of minerals and rocks. For the analysis of Ba-exchanged clays, Franzini's procedure has been modified slightly to account for the contribution of Ba to matrix effects.The new method, which furnishes both the CEC and the chemical compositions of the whole natural clay samples, has been tested on the eight ‘Source Clays’ of The Clay Minerals Society. The results compare well with data reported in the literature and confirm the accuracy and precision of the method and make it a valid alternative to techniques based on wet chemistry, execution of which is usually more time-consuming and which often requires greater analytical skill.

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