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Different solutions have been proposed over the years to optimize control of the temperature and atmosphere over a catalyst in order to reach an ideal reactor behavior. Here, a new innovative solution which aims to minimize temperature gradients along the catalyst bed is demonstrated. This was attained by focusing the infrared radiation generated from the heating elements onto the catalyst bed with the aid of an aluminium shield. This method yields a ∼0.13 K mm−1 axial temperature gradient ranging from 960 to 1173 K. With the selection of appropriate capillaries, pressures of 20 bar (2 MPa) can be attained. [ABSTRACT FROM AUTHOR]

At the High Energy Beamline ID15A at the European Synchrotron Radiation Facility we have developed a fast three-dimensional x-ray microtomography system, which acquires a complete dataset in typically less than 10 s. This unprecedented speed is achieved by combining a high efficiency phosphor screen, a reflecting microscope objective and a fast charge coupled device detector with the very intense high-energy white beam radiation provided by a wiggler source. The achieved spatial resolution is 2 μm. The available x-ray energy spectrum spans from 20 to 250 keV and can therefore be used for low and high Z materials. The spectrum can be modified by inserting different filters into the x-ray beam in order to optimize the signal-to-noise ratio and to avoid beam-hardening artifacts. Different phosphors with different energy sensitivity can be used. The very high speed allows in situ studies of systems evolving on the time scale of a few seconds or minutes. Three examples are given on sintering of metallic powders, solidification of binary alloys and liquid front propagation in granular materials. [ABSTRACT FROM AUTHOR]

Abstract: The use of synchrotron radiation X-ray microtomography rests on the exploitation of the beam coherence, the high spatial (submicron) or temporal resolution (s), in situ and real time experiments and quantitative measurements. Selected original applications showing these capabilities are presented. They include the phase contrast imaging of Si particles in Al alloys, the nucleation of fatigue cracks in structural materials, the visualization of hollow silica spheres within polymer foams, and the real time observation of the semi-solid state in Al–Cu alloys. [Copyright &y& Elsevier]