Fig. 17

Porosity distribution and representative elementary volume (REV) analysis for sample D1 in radial sections (top and middle). The left, binary segmented images highlight pores in black, with red and green circles denoting the regions of interest for REV analysis. The right porosity plotted against radial distance (in pixels). The red vertical line represents the chosen REV threshold, and the green line marks the maximum analysis radius. The top section shows higher porosity variations before stabilization, while the middle section exhibits a more gradual porosity increase, suggesting textural heterogeneity along the core length.