Publicaties
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On-chip non-dispersive infrared CO2 sensor based on an integrating cylinder Universiteit Gent
In this paper, we propose a novel, miniaturized non-dispersive infrared (NDIR) CO2 sensor implemented on a silicon chip. The sensor has a simple structure, consisting of a hollow metallic cylindrical cavity along with access waveguides. A detailed analysis of the proposed sensor is presented. Simulation with 3D ray tracing shows that an integrating cylinder with 4 mm diameter gives an equivalent optical path length of 3 . 5 cm. The ...
Hydrogen quantification in hydrogenated amorphous carbon films by infrared, Raman, and x-ray absorption near edge spectroscopies KU Leuven
In this study, we have employed infrared (IR) absorption spectroscopy, visible Raman spectroscopy, and x-ray absorption near edge structure (XANES) to quantify the hydrogen (HI) content in hydrogenated amorphous carbon (a-C: HI) films. a-C: H films with a hydrogen content varying from 29 to 47 at. % have been synthesized by electron cyclotron resonance chemical vapor deposition at low substrate temperatures (< 120 degrees C) applying a wide ...
The ID21 X-ray and infrared microscopy beamline at the ESRF: status and recent applications to artistic materials Universiteit Antwerpen KU Leuven
The ID21 beamline (European Synchrotron Radiation facility, France) is a multi micro-analytical platform combining X-ray and infrared micro-probes, for characterization of elements, species, molecular groups and crystalline structures in complex materials. Applications are mainly in the fields of cultural heritage, life science, environmental and earth sciences, materials sciences. Here, we first present the status of instruments: (i) the ...
Combined use of Synchrotron Radiation Based Micro-X-ray Fluorescence, Micro-X-ray Diffraction, Micro-X-ray Absorption Near-Edge, and Micro-Fourier Transform Infrared Spectroscopies for Revealing an Alternative Degradation Pathway of the Pigment Cadmium Ye KU Leuven Universiteit Antwerpen
Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO(4)·H(2)O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 μm sized globular agglomerations. Here, we study ...
Macroscopic Fourier transform infrared scanning in reflection mode (MA- rFTIR), a new tool for chemical imaging of cultural heritage artefacts in the mid-infrared range KU Leuven Universiteit Antwerpen
In this paper we demonstrate that by means of scanning reflection FTIR spectroscopy, it is possible to record highly specific distribution maps of organic and inorganic compounds from flat, macroscopic objects with cultural heritage value in a non-invasive manner. Our previous work involved the recording of macroscopic distributions of chemical elements or crystal phases from painted works of art based on respectively macroscopic X-ray ...
Discovery of a long-lived, high-amplitude dusty infrared transient KU Leuven
We report the detection of an infrared selected transient which has lasted at least 5 years, first identified by a large mid-infrared and optical outburst from a faint X-ray source detected with the Chandra X-ray Observatory. In this paper we rule out several scenarios for the cause of this outburst, including a classical nova, a luminous red nova, AGN flaring, a stellar merger, and intermediate luminosity optical transients, and interpret this ...
Chromium speciation methods and infrared spectroscopy for studying the chemical reactivity of lead chromate-based pigments in oil medium KU Leuven Universiteit Antwerpen
© 2015 Elsevier B.V. Environmental factors, such as light, humidity and temperature are triggering agents for the alteration of organic and/or inorganic constituents of oil paintings. The oxidation of the organic material is favored by increasing of relative humidity and temperature, whereas processes involving changes of the oxidation states of a number of inorganic pigments (e.g., vermilion, cadmium yellows, zinc yellows, chrome yellows) are ...
An integrated payload design for the Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) KU Leuven
© 2016 SPIE. ARIEL (the Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is one of the three candidates for the next ESA medium-class science mission (M4) expected to be launched in 2026. This mission will be devoted to observing spectroscopically in the infrared a large population of warm and hot transiting exoplanets (temperatures from ∼500 K to ∼3000 K) in our nearby Galactic neighborhood, opening a new discovery space in the field ...
GOODS-Herschel and CANDELS : the morphologies of ultraluminous infrared galaxies at z ∼ 2 Universiteit Gent
Using deep 100 and 160 mu m observations in GOODS-South from GOODS-Herschel, combined with high-resolution HST/WFC3 near-infrared imaging from CANDELS, we present the first detailed morphological analysis of a complete, far-infrared (FIR) selected sample of 52 ultraluminous infrared galaxies (ULIRGs; L-IR > 10(12) L-circle dot) at z similar to 2. We also make use of a comparison sample of galaxies with lower IR luminosities but with the same ...