Publications by authors named "Schoonjans Tom"

Seven particles captured by the Stardust Interstellar Dust Collector and returned to Earth for laboratory analysis have features consistent with an origin in the contemporary interstellar dust stream. More than 50 spacecraft debris particles were also identified. The interstellar dust candidates are readily distinguished from debris impacts on the basis of elemental composition and/or impact trajectory.

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Iron (Fe) is an essential element for plant growth and development; hence determining Fe distribution and concentration inside plant organs at the microscopic level is of great relevance to better understand its metabolism and bioavailability through the food chain. Among the available microanalytical techniques, synchrotron μ-XRF methods can provide a powerful and versatile array of analytical tools to study Fe distribution within plant samples. In the last years, the implementation of new algorithms and detection technologies has opened the way to more accurate (semi)quantitative analyses of complex matrices like plant materials.

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A stream of 1-20 μm sized mineral inclusions having the negative crystal shape of its host within an "ultra-deep" diamond from Rio Soriso (Juina area, Mato Grosso State, Brazil) has been studied with confocal μ-X-ray absorption near edge structure (μXANES) at the Fe K and Mn K edges. This technique allows the three-dimensional nondestructive speciation of the Fe and Mn containing minerals within the inclusion cloud. The observed Fe-rich inclusions were identified to be ferropericlase (Fe,Mg)O, hematite and a mixture of these two minerals.

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A confocal setup based on polycapillary half-lenses was used to demonstrate three-dimensional (3D) spatially resolved mu-XANES in fluorescence detection mode at the DUBBLE XAS station of the ESRF (BM26A). The incoming beam was focused using a polycapillary half-lens and a second glass polycapillary was placed in front of the energy dispersive detector to establish the confocal detection. The full-width-half-maxima along the main axes of the resulting ellipsoidal detection volume were 18.

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Unlabelled: Sandstones are used in many contemporary and historical buildings. With time, these buildings become dark and a surface crust is formed. Generally, these crusts mainly consist of minerals of which the constituents were mobilised from the interior of the stone, and material from the surrounding environment like air pollutants and dust.

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