Automated Analysis of Spatially Resolved X-ray Scattering and Micro Computed Tomography of Artificial and Natural Enamel Carious Lesions

Grazing-incidence small-angle X-ray scattering (GISAXS) coupled with computed tomography (CT) has enabled the visualization of the spatial distribution of nanostructures in thin films. 2D GISAXS images are obtained by scanning along the direction perpendicular to the X-ray beam at each rotation angle. Because the intensities at the q positions contain nanostructural information, the reconstructed CT images individually represent the spatial distributions of this information (e.g. size, shape, surface, characteristic length). These images are reconstructed from the intensities acquired at angular intervals over 180°, but the total measurement time is prolonged. This increase in the radiation dosage can cause damage to the sample. One way to reduce the overall measurement time is to perform a scanning GISAXS measurement along the direction perpendicular to the X-ray beam with a limited interval angle. Using filtered back-projection (FBP), CT images are reconstructed from sinograms with limited interval angles from 3 to 48° (FBP-CT images). However, these images are blurred and have a low image quality. In this study, to optimize the CT image quality, total variation (TV) regularization is introduced to minimize sinogram image noise and artifacts. It is proposed that the TV method can be applied to downsampling of sinograms in order to improve the CT images in comparison with the FBP-CT images.

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Anomalous dynamic response of nematic platelets studied by spatially resolved rheo-small angle x-ray scattering in the 1–2 plane

Physics of Fluids ◽

10.1063/5.0069458 ◽

2021 ◽

Vol 33 (12) ◽

pp. 123104

Author(s):

O. Korculanin ◽

F. Westermeier ◽

H. Hirsemann ◽

B. Struth ◽

D. Hermida-Merino ◽

...

Keyword(s):

Dynamic Response ◽

Small Angle ◽

X Ray ◽

Spatially Resolved ◽

X Ray Scattering ◽

Ray Scattering

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Direct tomography imaging for inelastic X-ray scattering experiments at high pressure

Journal of Synchrotron Radiation ◽

10.1107/s1600577516017100 ◽

2017 ◽

Vol 24 (1) ◽

pp. 269-275 ◽

Cited By ~ 14

Author(s):

Ch. J. Sahle ◽

A. D. Rosa ◽

M. Rossi ◽

V. Cerantola ◽

G. Spiekermann ◽

...

Keyword(s):

High Pressure ◽

Machine Learning Algorithms ◽

Raman Scattering Spectroscopy ◽

X Ray ◽

Spatially Resolved ◽

X Ray Scattering ◽

Sample Edge ◽

Pressure Medium ◽

Diamond Anvils ◽

Ray Scattering

A method to separate the non-resonant inelastic X-ray scattering signal of a micro-metric sample contained inside a diamond anvil cell (DAC) from the signal originating from the high-pressure sample environment is described. Especially for high-pressure experiments, the parasitic signal originating from the diamond anvils, the gasket and/or the pressure medium can easily obscure the sample signal or even render the experiment impossible. Another severe complication for high-pressure non-resonant inelastic X-ray measurements, such as X-ray Raman scattering spectroscopy, can be the proximity of the desired sample edge energy to an absorption edge energy of elements constituting the DAC. It is shown that recording the scattered signal in a spatially resolved manner allows these problems to be overcome by separating the sample signal from the spurious scattering of the DAC without constraints on the solid angle of detection. Furthermore, simple machine learning algorithms facilitate finding the corresponding detector pixels that record the sample signal. The outlined experimental technique and data analysis approach are demonstrated by presenting spectra of the SiL2,3-edge and OK-edge of compressed α-quartz. The spectra are of unprecedented quality and both the OK-edge and the SiL2,3-edge clearly show the existence of a pressure-induced phase transition between 10 and 24 GPa.

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A radially accessible tubular in situ X-ray cell for spatially resolved operando scattering and spectroscopic studies of electrochemical energy storage devices

Journal of Applied Crystallography ◽

10.1107/s1600576716012632 ◽

2016 ◽

Vol 49 (5) ◽

pp. 1665-1673 ◽

Cited By ~ 18

Author(s):

Hao Liu ◽

Phoebe K. Allan ◽

Olaf J. Borkiewicz ◽

Charles Kurtz ◽

Clare P. Grey ◽

...

Keyword(s):

Energy Storage ◽

Electrochemical Cell ◽

Spectroscopic Studies ◽

Energy Storage Devices ◽

X Ray ◽

Spatially Resolved ◽

X Ray Scattering ◽

Battery Electrode ◽

Electrochemical Double Layer ◽

Ray Scattering

A tubular operando electrochemical cell has been developed to allow spatially resolved X-ray scattering and spectroscopic measurements of individual cell components, or regions thereof, during device operation. These measurements are enabled by the tubular cell geometry, wherein the X-ray-transparent tube walls allow radial access for the incident and scattered/transmitted X-ray beam; by probing different depths within the electrode stack, the transformation of different components or regions can be resolved. The cell is compatible with a variety of synchrotron-based scattering, absorption and imaging methodologies. The reliability of the electrochemical cell and the quality of the resulting X-ray scattering and spectroscopic data are demonstrated for two types of energy storage: the evolution of the distribution of the state of charge of an Li-ion battery electrode during cycling is documented using X-ray powder diffraction, and the redistribution of ions between two porous carbon electrodes in an electrochemical double-layer capacitor is documented using X-ray absorption near-edge spectroscopy.

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Towards quantitative demineralization imaging for the assessment of carious lesions based on PS-OCT

EPJ Web of Conferences ◽

10.1051/epjconf/202023804009 ◽

2020 ◽

Vol 238 ◽

pp. 04009

Author(s):

Jonas Golde ◽

Florian Tetschke ◽

Robin Vosahlo ◽

Lars Kirsten ◽

Julia Walther ◽

...

Keyword(s):

Computed Tomography ◽

Optical Coherence Tomography ◽

Optical Coherence ◽

Micro Computed Tomography ◽

X Ray ◽

High Interest ◽

Enamel Demineralization ◽

Carious Lesions ◽

Conservative Dentistry

Assessing the stage and progression of enamel demineralization non-invasively is of high interest in conservative dentistry. By examining tooth samples with suspected occlusal lesions, we show the potential of depolarization imaging based on polarization-sensitive optical coherence tomography for the assessment of carious lesions and validate the results by co-registered X-ray micro-computed tomography volumes.

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