When cracks form in a thin contracting layer, they sequentially break the layer into smaller and smaller pieces. A rectilinear crack pattern encodes information about the order of crack formation, as later cracks tend to intersect with earlier cracks at right angles. In a hexagonal pattern, in contrast, the angles between all cracks at a vertex are near 120 degrees. Hexagonal crack patterns are...

Outcrops of columnar joints made solidified lava flows are often covered by semiordered polygonal cracks. The polygon diameters fairly uniform at each outcrop, but their shapes largely vary in the number sides and internal angles. Herein, we unveil that statistical variation shape follows an extreme value distribution class: Gumbel distribution. law was found to hold for different joints, regar...

Starch-water slurries are commonly used to study fracture dynamics. Drying starch cakes benefit from being simple, economical, and reproducible systems, and have been used to model desiccation fracture in soils, thin-film fracture in paint, and columnar joints in lava. In this paper, the physical properties of starch-water mixtures are studied, and used to interpret and develop a multiphase tra...

Crack patterns in laboratory experiments on thick samples of drying cornstarch are geometrically similar to columnar joints in cooling lava found at geological sites such as the Giant's Causeway. We present measurements of the crack spacing from both laboratory and geological investigations of columnar jointing, and show how these data can be collapsed onto a single master scaling curve. This i...

A comparative petrological study was conducted on the columnar joints of Guryongpo, Pohang, Yangnam, Gyeongju, and Gangdong-hwaam, Ulsan in Cenozoic Miocene sedimentary basin. Horizontal joints, these are characteristically developed, cross-sectional shape each joint is predominantly quadrilateral pentagonal Guryongpo Yangnam to hexagonal Gangdong-hwaam joint. As a result XRF analysis, it confi...

simultaneous dislocation of both interphalangeal (ip) joints of same finger is a highly uncommon finding. and dislocation of metacarpophalangeal (mcp) joint along with interphalangeal joints of thumb are reported in literatures if, scarcely. here we are reporting the three cases, comprising of double dislocation of ip joints in little finger in two patients and simultaneous mcp and ip joint dis...

In order to improve the performance of welded joints in Al-Li alloys, butt consisting 2 mm thick 2195-T8 alloy plates are fabricated by laser beam welding with different filler wires this paper. The ER2319CT, ER4047, and without investigated context microstructure, distribution alloying elements, burning loss tensile strength. From fusion boundary center weld seam (WS), crystal morphologies var...