Publications

The domain of diffusion weighted imaging (DWI) has come a long way since its initial development in the mid-1980s. Over the years, we have gained a better understanding of the accompanying techniques and necessary processing steps involved, furthermore leading to a wealth of new insights in the complex workings of the (human) brain. The introduction of diffusion tensor imaging (DTI) has played a crucial role in thisprocess, as it provided the ...

Copyright © 2017 Elke Jacops et al. In order to investigate in more detail the relation between the size of diffusing molecules and their diffusion coefficients (and geometric factors), diffusion experiments with gases of different size and tritiated water (HTO) have been performed on different clayey samples (Boom Clay, Eigenbilzen Sands, Opalinus Clay, Callovo-Oxfordian Clay, and bentonite with different dry densities). We observed that, for ...

The improvement of supercritical fluid chromatography (SFC) instrumentation enhanced its reliability and utility over the past decade. The further development of high speed and high resolution separations is however obstructed by the lack of accurate models for axial dispersion in SFC. This work is a first step to tackle this by developing more reliable methods to measure molecular (Dmol) and longitudinal diffusion (Deff) in SFC, as these affect ...

In this work we investigate the well-posed for diffusion equations associated to subelliptic pseudo-differential operators on compact Lie groups. The diffusion by strongly elliptic operators is considered as a special case and in particular the fractional diffusion with respect to the Laplacian. The general case is studied within the Hormander classes associated to a sub-Riemannian structure on the group (encoded by a Hormander system of vector ...

Multi-spacecraft observations of widespread solar energetic particle (SEP) events indicate that perpendicular (to the mean field) diffusion is an important SEP transport mechanism. However, this is in direct contrast to so called spike and drop-out events, which indicate very little lateral transport. To better understand these seemingly incongruous observations, we discuss the recent progress made towards understanding and implementing ...

The interfacial reactions and growth behavior of the Cu3Sn and Cu6Sn5 phases in Sn-3.0%Ag-0.5%Cu/Cu and Sn-3.5%Ag-0.7%Cu/Cu diffusion couples were investigated at 130 °C, 150 °C, 170 °C and 200 °C and compared with those in binary Sn/Cu diffusion couples using identical experimental conditions. The Ag solubility in the Cu3Sn and Cu6Sn5 phases was found to be quite small. The parabolic growth constants of Cu3Sn and Cu6Sn5 in Sn-xAg-yCu/Cu ...

The diffusion behaviors and diffusion parameters of intermetallic compounds (IMCs) formed in Cu-Sn diffusion couples were investigated at the temperature range of 130 °C–200 °C. Interdiffusion coefficients of IMCs were calculated based on the measured composition profiles of the diffusion zones. Considering the wavy type of the diffusion layers and the narrow homogeneity range of the IMCs (Cu₃Sn and Cu₆Sn₅), the integrated method was performed ...