161 research outputs found
Scanning X-ray micro-fluorescence study of hydrogels as a matrix for the immobilization of redox enzymes
High spectral and spatial resolution X-ray transmission radiography and tomography using a Color X-ray Camera
High resolution X-ray radiography and computed tomography are excellent techniques for non-destructive characterization of an object under investigation at a spatial resolution in the micrometer range. However, as the image contrast depends on both chemical composition and material density, no chemical information is obtained from this data. Furthermore, lab-based measurements are affected by the polychromatic X-ray beam, which results in beam hardening effects. New types of X-ray detectors which provide spectral information on the measured X-ray beam can help to overcome these limitations. In this paper, an energy dispersive CCD detector with high spectral resolution is characterized for use in high resolution radiography and tomography, where a focus is put on the experimental conditions and requirements of both measurement techniques
Investigation of copper accumulation in the marine bivalve mollusc Mytilus edulis with Zone plate optics
A novel three-dimensional elemental imaging method based on full-field X-ray fluorescence detection technology
In vivo X-ray fluorescence microimaging of biological model organisms manipulated by laser-based optical tweezers
Chemical imaging of mixed metal oxide catalysts for propylene oxidation: from model binary systems to complex multicomponent systems
Industrially-applied mixed metal oxide catalysts often possess an ensemble of structural components with complementary functions. Characterisation of these hierarchical systems is challenging, particularly moving from binary to quaternary systems. Here a quaternary Bi−Mo−Co−Fe oxide catalyst showing significantly greater activity than binary Bi−Mo oxides for selective propylene oxidation to acrolein was studied with chemical imaging techniques from the microscale to nanoscale. Conventional techniques like XRD and Raman spectroscopy could only distinguish a small number of components. Spatially-resolved characterisation provided a clearer picture of metal oxide phase composition, starting from elemental distribution by SEM-EDX and spatially-resolved mapping of metal oxide components by 2D Raman spectroscopy. This was extended to 3D using multiscale hard X-ray tomography with fluorescence, phase, and diffraction contrast. The identification and co-localisation of phases in 2D and 3D can assist in rationalising catalytic performance during propylene oxidation, based on studies of model, binary, or ternary catalyst systems in literature. This approach is generally applicable and attractive for characterisation of complex mixed metal oxide systems. © 2021 The Authors. ChemCatChem published by Wiley-VCH Gmb
Synchrotron radiation X-ray fluorescence imaging of biological model organisms manipulated by laser-based optical tweezers
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