Porosity image

The three-dimensional porosity image of MAG sample is shown in Fig. 9. The porosity image is displayed as a series of two-dimensional images, each of which represents a plane of voxels sliced perpendicularly to the other direction. In Fig. 9, axial limits of the sample are apparent. The middle slices have more columns of voxels which are inside the sample than the others, due to the cylindrical shape of the sample. The white spots above the sample are attributed to the signal corresponding to the fluid in the reference. The resolution is poor because the voxel... 

Slice 1 Slice2 Slice 3 Slice 4 Slice 5 Slice6 Slice 7 Slice 8 Fig. 9. Three-dimensional porosity image of a cylindrically shaped sample (MAG). 

The principal object of this article is the description and the development of a software which makes it possible to simulate in real time the circulation of a fluid in a porous rock. We obtain not only rock parameters (porosity, radius of penes connection), but we ala> observe the progression of the fluid in the rock (phenomraxm of deflation). In the second time we explain the first results which we obtained with these simulations that we will compare these results 2D with the data 3D of porosity per mercury injection to allow us to establish a link between porosity image 2D and the data 3D. 

Fig. 2 Single slice of porosity in ferritic weld (a) original image, (b) image recontruction without noise, (c) image reconstruction with noise.

Simulations of the adaptive reconstruction have been performed for a single slice of a porosity in ferritic weld as shown in Fig. 2a [11]. The image matrix has the dimensions 230x120 pixels. The number of beams in each projection is M=131. The total number of projections K was chosen to be 50. For the projections the usual CT setup was used restricted to angels between 0° and 180° with the uniform step size of about 3.7°. The diagonal form of the quadratic criteria F(a,a) and f(a,a) were used for the reconstruction algorithms (5) and (6). 

Fig. 1. Experimental restored acoustical tomographic images of defects in product sections (a-dififerent density 5p 10%, b- porosity x,y- in mm).

Catalyst films for electrochemical promotion studies should be thin and porous enough so that the catalytic reaction under study is not subject to internal mass-transfer limitations within the desired operating temperature. Thickness below 10 pm and porosity larger than 30% are usually sufficient to ensure the absence of internal mass-transfer limitations. Several SEM images of such catalyst films have been presented in this book. SEM characterization is very important in assessing the morphological suitability of catalyst films for electrochemical promotion studies and in optimizing the calcination procedure. 

Overall platelet dimensions of mineral aurichalcite did not appear to change during calcination, but became polycrystalline and porous. By dark field Imaging in the TEM, the ZnO particles were observed to be uniformly and highly dispersed. The porosity can be accounted for by the approximately threefold increase in density of Zn atoms upon decomposition of aurichalcite to ZnO. For this density change to occur with a constant overall platelet volume, pores must form. 

J. Gotz, K. Zick, C. Heinen, T. Konig 2002, (Visualisation of flow processes in packed beds with NMR imaging Determination of the local porosity, velocity vector and local dispersion coefficients), Chem. Eng. Process. 41 (7), 611-630. 

Fig. 3.5.7 NMR image of imbibed c-C4Fg gas in a 35 and 40% porosity Y-TZP ceramic, containing an alumina surface treatment. Adapted from Ref. [20].

W. A. Ellingson, J. L. Ackerman, L. Garrido, J. D. Weyand, R. A. Dimilia 1987, (Characterization of porosity in green-state and partially densified AI2O3 by nuclear magnetic resonance imaging), Ceram. Eng. Sci. Proc. 8, 503—512. 

A local variation in porosity can be produced by an inhomogeneous illumination intensity. However, any image projected on the backside of the wafer generates a smoothed-out current density distribution on the frontside, because of random diffusion of the charge carriers in the bulk. This problem can be reduced if thin wafers or illumination from the frontside is used. However, sharp lateral changes in porosity cannot be achieved. 

Overall the spheres were of good quality judging from images obtained and could be used for filling with sodium alanate. However, to confirm through wall open porosity formation across the spheres wall, approximately 900 A cross section was made across a sphere wall and SEM and elemental mapping was conducted and Fig. 3 shows the results obtained. 

Figure 33. High-resolution field emission SEM of a porous LSM/YSZ interface following polarization for 3 h at —0.8 V at 950 °C in air. The porosity evident at the TPB is not seen in images taken prior to polarization. (Reprinted with permission from ref 214. Copyright 2003 Elsevier.)...

Very interestingly, the IPD is found to show practically no or very little dependence on the volume fraction and only depends on the reaction rate (Fig. 35). Here the IPD is calculated from the mean diameter taken from image analysis and the volume fraction, which has been determined directly from the porosity of these macroporous thermosets. Both values could be determined experimentally with high accuracy and no simplifications are needed for the calculations. 

In addition to Au, a variety of Au-Sb, Au-Ag and Bi-Te alloys accompanied post-D2 arsenopyrite precipitation. Au and Bi-Te alloys are also locally concentrated in the biotite-rich margins of tonalite dykes that were contaminated by the host sediments. These alloys also appear to be concentrated within the HGA and are locally associated with disseminated scheelite and F-apatite. The latter also occur in late-stage veins that cross-cut weakly foliated granodiorite stocks that lie immediately beneath the HGA. A combination of BSE and CL imaging reveals that precipitation of these post-D2 sulfides and alloys occurred within a micro-porosity network that records dissolution-precipitation reactions... 

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