Publications

Background: X-ray methods have proven to be reliable, accurate and sensitive techniques to study activated carbons in order to define its porous structure and functionality groups. Methods: For the first time, the characterization of the exhaustion level of granular activated carbon (GAC) used in rum production applying methods based on X-ray technology has been explored. In this work, the exhaustion degree of GAC from a target rum "filter" ...

X-ray radiographic images of paintings often show little or no contrast. In order to increase the contrast in radiographic images we measured the X-ray spectrum of a low power X-ray tube, after passing through the painting, with a high energy-resolution SDD detector. To obtain images, the detector is collimated with a 400 mu m diameter pinhole and the painting was moved through the beam in the x and y-direction using a dwell time of a few ...

Samples of Savonnie`res limestone subjected to repeated wettingU+2013drying cycles were investigated by both neutron radiography and X-ray micro-tomography to collect information on saline uptake and salt precipitation. Capillary uptake of water, 1.4 molal sodium sulphate and 5.8 molal sodium chloride solution was visualized with neutron radiography. The liquid penetration coefficients and diffusivities were determined and are markedly lower for ...

This article presents a comprehensive study on saline transport, pore filling due to salt crystallization and resulting salt damage in Savonnières limestone. The results were achieved by combining neutron radiography - for transport imaging - and X-ray micro-tomography - for pore structure and fracture visualization U+2013 applied to samples subjected to repeated wetting-drying cycles. We studied capillary uptake and drying of water, 1.4m sodium ...

Corrosion of steel reinforcement is one of the most detrimental attack mechanisms for reinforced concrete structures. The presence of cracks, which are inextricably linked to reinforced concrete, accelerates this attack mechanism. The aim of this study is to heal cracks by an autonomous mechanism, which is triggered upon crack appearance. With an accelerated corrosion test on mortar samples with embedded reinforcement bars, it is shown that the ...

In high-resolution radiography and tomography, the local intensity of the X-ray beam is typically measured using an energy-integrating detector system, thus discarding all information on the detected X-ray spectrum. Recently, several direct or hybrid detector systems have been developed which allow for single photon counting using one or more energy thresholds [1]. By measuring the same object at different energy thresholds, it becomes possible ...

X-ray radiography is widely used as a non-destructive method for defect detection and quality checks of nuclear fuel rod’s components in the fabrication process. In this paper, an approach based on Monte Carlo method is proposed to obtain optimum filter and exposure parameters such tube voltage, current and exposure for digital radiography of a nuclear fuel rod including UO2 pellets with a maximum diameter of 11.9 mm. Monte Carlo N-Particle ...

The heel effect in X-ray radiation imaging systems causes a non-uniform radiation distribution on the imaging plane. In this research, a novel method was developed for predicting the pixel value’s non-uniformity due to the heel effect of X-ray tube on the imaging plane using Monte Carlo N particle (MCNP) simulation code and artificial neural network (ANN). At first, an industrial X-ray tube and a computed radiography (CR) image plate were ...

The migration of moisture in cores of porous homogeneous sandstone of Ledian age (Belgian Eocene, Tertiary) is monitored with PET (Positron Emission Tomography) and micro-focus X-ray radiography. In the case of PET, a nuclear medical imaging technique, Co-55-EDTA (Ethylenediamine Tetraacetic acid) and R-F-18 were used as water-soluble tracers. The X-ray projection method has evolved from the better-known medical technique and allows a fast and ...