Topological mechanical states in geometry-driven hyperuniform materials.

Disordered hyperuniform materials are increasingly drawing attention due to their unique physical properties, associated with global isotropy and locally broken orientational symmetry, that set them apart from traditional crystalline materials. Using a dynamic space-partitioning process, we generate disordered hyperuniform cellular structures where distinct patterns of pentagonal and heptagonal topological defects emerge within hexagonal domains. The microscopic defect dynamics are guided by local topological transitions, commonly observed in viscoelastic systems.

Mixing properties of bi-disperse ellipsoid assemblies: mean-field behaviour in a granular matter experiment.

The structure and spatial statistical properties of amorphous ellipsoid assemblies have profound scientific and industrial significance in many systems, from cell assays to granular materials. This paper uses a fundamental theoretical relationship for mixture distributions to explain the observations of an extensive X-ray computed tomography study of granular ellipsoidal packings. We study a size-bi-disperse mixture of two types of ellipsoids of revolutions that have the same aspect ratio of ≈ 0.

A versatile microtomography system to study in situ the failure and fragmentation in geomaterials.

This article describes a microtomography experimental platform enabling in situ micro-mechanical study of failure and fragmentation in geomaterials. The system is based on an original high-pressure triaxial flow cell, which is fully integrated into a custom built microtomography scanner equipped with a laboratory x-ray source. The design of the high-precision mechanical apparatus was informed by the concurrent development of advanced tomographic reconstruction methods based on helical scanning and of algorithms correcting for hardware inaccuracies.

Low radiodensity μCT scans to reveal detailed morphology of the termite leg and its subgenual organ.

Termites sense tiny substrate-borne vibrations through subgenual organs (SGOs) located within their legs' tibiae. Little is known about the SGOs' structure and physical properties. We applied high-resolution (voxel size 0.

Topological signatures and stability of hexagonal close packing and Barlow stackings.

Two common representations of close packings of identical spheres consisting of hexagonal layers, called Barlow stackings, appear abundantly in minerals and metals. These motifs, however, occupy an identical portion of space and bear identical first-order topological signatures as measured by persistent homology. Here we present a novel method based on -fold covers that unambiguously distinguishes between these patterns.