Particle movement during the deep penetration of a granular material studied by X-ray microtomography

2006 ◽  
Vol 54 (2) ◽  
pp. 191-196 ◽  
Author(s):  
S.A. McDonald ◽  
L.C.R. Schneider ◽  
A.C.F. Cocks ◽  
P.J. Withers
2020 ◽  
Vol 65 (14) ◽  
pp. 145012
Author(s):  
Mark Gardner ◽  
David Parsons ◽  
Kaye Morgan ◽  
Alexandra McCarron ◽  
Patricia Cmielewski ◽  
...  

1988 ◽  
Vol 32 ◽  
pp. 311-321 ◽  
Author(s):  
R.A. Larsen ◽  
T.F. McNulty ◽  
R.P. Goehner ◽  
K.R. Crystal

AbstractThe use of conventional θ/2θ diffraction methods for the characterization of polycrystalline thin films is not in general a satisfactory technique due to the relatively deep penetration of x-ray photons in most materials. Glancing incidence diffraction (GID) can compensate for the penetration problems inherent in the θ/2θ geometry. Parallel beam geometry has been developed in conjunction with GID to eliminate the focusing aberrations encountered when performing these types of measurements. During the past yearwe developed a parallel beam attachment which we have successfully configured to a number of systems.


2011 ◽  
Vol 183 ◽  
pp. 89-94 ◽  
Author(s):  
Anna Iwulska ◽  
G. Sliwinski

The titanium dioxide target (99.7%) of 1 cm in dia was ablated in vacuum by laser pulses (6 ns) at 266 nm and at repetition rate of 10 Hz. During deposition the laser fluence between 1 and 3.5 J/cm2 and the O2 pressure from the range of 10-2 – 1 Pa were applied. The thin TiO2 films were deposited on glass substrate (1 × 1 cm2) heated up to 500 °C. The chemical composition of the film and samples produced by annealing were investigated by spectroscopic techniques (μ-Raman, EDX) and the structure, porosity and surface morphology were analysed by means of SEM and x-ray diffraction (XRD). The SEM inspection of the TiO2 thin film samples indicates that the obtained material is mostly crystalline. After annealing in O2 at 500 °C the structure characterized by the presence of both anatase and rutile phases is observed in the Raman spectra and confirmed by the XRD data. The phase content ratio depends on the O2 pressure applied. Results confirm that nanostructures produced in this way represent densely packed columns and promote deep penetration of guest particles such as CO2.The resulting large active surface is advantageous from the point of view of photocatalytic applications.


2005 ◽  
Vol 490-491 ◽  
pp. 19-27
Author(s):  
Makoto Hayashi ◽  
Shinobu Okido

In the X-ray diffraction method, the diffraction intensity, the half-value width, the residual stress and the amount of residual austenitic phase can be measured. By using these parameters, the quality, the mechanical properties and the fatigue strength of materials, the remaining life of fatigue and creep can be evaluated. While the X-ray study has been widely performed for the various kinds of industrial fields in the laboratory, the applications to the actual structure and components have not so many. However, the small size X-ray residual stress analyzer, the position sensitive detector and the micro area diffraction apparatus have been developed for these twenty years. Thus the X-ray diffraction methods have been variously applied to the industrial fields. The X-ray diffraction methods were used to be applied for the large scale structures and machine parts, but recently applied to the semi-conductor fields. On the other hand, the neutron diffraction method has been introduced to measure the residual stresses in the internals of components because of its deep penetration depth. Based on the experiences of X-ray diffraction method, the various kinds of techniques have been proposed. In this paper, the applications of X-ray and neutron diffraction method to the reliability evaluations of structural components and the electronic devices are described.


2012 ◽  
Vol 201-202 ◽  
pp. 356-359
Author(s):  
Jun Bin Xiang ◽  
Xiang Dong Gao

Owing to a strong capability of penetration, the radiography can be used to observe and analyze the formation of a molten pool inside weldments during laser deep penetration welding. The shape of a molten pool and the thermal transmit of laser through keyhole can be monitored and analyzed in real-time. During a high-power fiber laser bead on plate welding of Type 304 stainless steel, a high-speed radiography camera was employed to capture the molten pool images. These captured X-ray images were degraded by the disturbance and noises from the welding process and radiography devices. This paper proposes an efficient arithmetic to restore and enhance the X-ray images of molten pools. The point spread function (PSF) of X-ray image degeneration was obtained through blind deconvolution, And the PSF was applied as a parameter to implement the constrained least squares filtering of X-ray image of a molten pool. Also, the X-ray image was enhanced by contrast stretching transformation. Experimental results showed that the proposed arithmetic of image restoration and enhancement could improve the quality of X-ray images efficiently and protrude the contour feature of a molten pool.


2017 ◽  
Vol 22 (2) ◽  
pp. 49-56
Author(s):  
Selam Waktola ◽  
Andre Bieberle ◽  
Frank Barthel ◽  
Martina Bieberle ◽  
Uwe Hampel ◽  
...  

Abstract This paper presents an application of an ultrafast electron beam X-ray CT scanner for investigating the gravitational flow behavior of granulates through cylindrical silo model. The CT scanner allows obtaining crosssectional images of the granular material distribution with a spatial resolution of approximately 1 mm and a time resolution of 2 kHz. In order to conduct a deep analysis of the granular flow concentration changes, two image processing algorithm steps were applied. The first step deals with preprocessing and re-centering stacks of raw images. The second step divides the preprocessed image into several concentric rings and calculates the mean value to study radial concentration changes. Independent analysis of granular concentration in each ring provides useful knowledge to study the silo discharging during mass flow and funnel flow.


2008 ◽  
Vol 07 (01) ◽  
pp. 161-165 ◽  
Author(s):  
TONG WEN ◽  
XIA CHEN ◽  
WALTER RUZIWA ◽  
ALAN COCKS

The flow pattern of loose powders indented by a rigid punch in an open cylindrical die was studied using the discrete element method (DEM) and the finite element method (FEM) using the Drucker-Prager/CAP material model. The results are compared with those obtained through X-ray microtomography studies of particle movement during the deep penetration of a granular material. The density distribution of the granular material and trajectories of the particles during the deep penetration of the punch are analyzed. It is observed that in the vicinity of the punch, several kinds of flow patterns occur simultaneously, and the shear produces a relatively low density. Typical particle displacement and particle density distributions can be observed in both the numerical simulations and experimental studies. This study demonstrates that DEM and FEM can capture the main features of the powder flow behaviour during low-pressure compaction.


Author(s):  
Zafar U. Koreshi ◽  
Sadaf Siddiq ◽  
Irfan A. Khan ◽  
Tasneem Shah

An interaction probability model is used to model the Energy Dispersive X-Ray Fluorescent (EDXRF) response from a given gold sample to determine the purity (or karatage) of gold. The application of this model is considered for estimating experimental results using a spectrometer with a X-Ray source of 18.6 keV which counts L-shell fluorescence in gold. In the elementary model, Compton scattering is largely ignored as it forms an insignificant contribution compared with photoelectric absorption in the energies of interest. The model is used to infer the “average depth” to which this analysis can be expected to provide reliable results, since ‘depth profiling’ is a major limitation of XRF. This model is further strengthened by carrying out a ‘deep-penetration’ analysis for the energy-dependent photon transport equation with the moments method. The first four moments are computed and used to obtain the spatial profile for the energy-dependent photon flux in the vicinity of L-shell phenomena. This analysis is useful to understand the contribution from interaction phenomena deeper within the material. For validation of depth profile, 2 gold-coated discs of thickness 10 microns and 40 microns were analyzed on the same XRF spectrometer. Transport theory depth-profiling results were validated from detection of the nickel-silver substrate of the discs.


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