Fig. 16

Porosity distribution and representative elementary volume (REV) analysis for sample B4 in both radial and axial orientations. The left images show binary segmented images with red and green contours indicating the regions of interest. The right image displays porosity as a function of sampling radius (in pixels). The red vertical line marks the selected REV threshold, while the green line indicates the maximum analysis radius. In the radial section, porosity increases gradually with radius, stabilizing near the REV. In the axial section, porosity shows a rapid initial rise followed by stabilization, suggesting a more homogeneous structure.