Fig. 5.

(A) Sketch illustrating the foam lid used to prevent the height increase of the granular assembly. (B) Bar-chart showing a comparison between the measured steady state crystallization level ${\phi }_{\mathit{ss}}$ for vibration at an amplitude $ɑ=2 \text{mm}$ and frequency ƒ = 90 Hz with and without the foam lid. The corresponding discrete element predictions are also included as dashed lines. For comparison purposes, the maximum value of ${\phi }_{\mathit{ss}}$ from Fig. 1C (which corresponded to ƒ = 20 Hz at $a=2 \text{mm}$ ) is also included. (C) High-speed photography measurements of the magnitude $〈\left|v\right|〉$ of the average velocities of balls on the $z-x$ plane located on the $y=0$ surface of the box. These velocities are averaged over 30 cycles after steady-state crystallization has been attained for vibration at an amplitude $\text{a}=2 \text{mm}$ and ƒ = 90 Hz for the assembly capped by the foam lid. (D) Corresponding XCT measurements to show the movement of 200 tracer balls from the wall of the box into the bulk after subjecting the assembly to 1,000 vibration cycles.