Scaling laws of plume-induced granular cratering.

Extraterrestrial landing often requires firing a high-speed plume towards a planetary surface, and the resulting gas-granular interactions pose potential hazards to the lander. To investigate these jet-induced cratering dynamics, an experiment campaign covering a range of gas and granular properties relevant to the lunar and Martian environments was conducted in a large-scale vacuum chamber. Despite the variations in jet Mach number, mass flow rate, and composition of the granular phase investigated in this work, the observed time evolution of crater depth displays a consistent transition from an early-stage linear to a late-stage sublinear growth.

Isolated tear of the pectoralis minor tendon in a high school football player.

Multiple pectoralis major tendon tears have been reported in the literature; however, isolated rupture of the pectoralis minor tendon is rare and has been reported 3 times (4 patients).This article describes a case of an isolated pectoralis minor tendon tear in a male high school football player after a traumatic injury. The patient was injured while making a tackle and leading with his arm and chest.