STEAM imaging

Fig. 6.2.5 [FRAl] Timing diagrams of basic STEAM imaging sequences. Schemes (a)-

Fig. 7.2.6 [Haa3] Pulse sequences for CHESS-STEAM imaging. The NMR signals are the Hahn or spin echo (HE) and the stimulated echo (STE). (a) Basic sequence for chemical-shift selective measurement of HE and STE images, (b) Sequence for acquisition of n slice-selective images from CHESS stimulated echoes.

Fig. 7.2.7 [Haa3] Multi-CHESS-STEAM imaging, (a) Simultaneous acquisition of one nonselective HE image and n CHESS-STEAM images from one slice, (b) Multi-slice double CHESS-STEAM method for simultaneous acquisition of two CHESS images at n slices.

Progress in mean of modelisation and inverse problem solving [1] let us hope to dispose soon of these tools for flaws 3D imaging in Non Destructive Control with eddy current sensors. This will achieve a real improvement of the actual methods, mainly based upon signature analysis. But the actual eddy current probes used for steam generators tubes inspection in nuclear industry do not produce the adequate measurements and/or are not modelisable. 

The TEM images of deposits observed on Catalyst I used for the steam reforming of naphthalene are shown in Fig. 5. Two types of deposits were observed and they were proved to be composed of mainly carbon by EDS elemental analysis. One of them is film-like deposit over catalysts as shown in Fig. 5(a). This type of coke seems to consist of a polymer of C H, radicals. The other is pyrolytic carbon, which gives image of graphite-like layer as shown in Fig. 5(b). Pyrolytic carbon seems to be produced in dehydrogenation of naphthalene. TPO profile is shown in Fig. 6. The peaks around 600 K and 1000 K are attributable to the oxidation of film-like carbon and pyrolytic carbon, respectively [11-13]. These results coincide with TEM observations. 

Donaldson, M. R., and R. E. Pulfrey, 1979, Imaging Optical Probe for Pressurized Steam-Water Environments, Proc. Review Group Conf. on Advanced Instrument for Reactor Safety Research, USNRC, NUREG/CP-0007, III.17-1-27. (3)... 

In 1900, there were only a few thousand motor vehicles in the United States and the public had a choice between steam, electric, or gasoline automobiles. A gasoline-based transportation system was not a foregone conclusion. The public had become used to horses and the image of sitting near a boiler, battery or gas tank and moving by a series of explosions, was not attractive. 

Figure 16.2 Transmission electron microscopy image of steam-stabilized Y zeolite showing mesopore network.

In cyclic impregnated catalysts, Ni is mainly present on the catalyst surface. In contrast a vanadium profile over the particle is found. In the case that no steam is applied in the regeneration stage of the cyclic deactivation procedure, the V remains mainly concentrated at the surface of the catalyst particles. Other methods as imaging SIMS (19) and Luminescence (20) are also being applied to monitor and compare the Ni and V distribution of deactivated... 

Figure 6 Silicon EDS map (left) and SEM secondary image (right) of a cross-section of a steam/hydrogen electrode near the sealing edge of the cell...

Figure 7 SEM images and EDS maps of the interface between the interconnect and bond layer, which bonds the interconnect to the steam/hydrogen flow field...

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