This paper aims to introduce a new non-destructive testing technique in use for detecting the occurrence of material instability and a specific data reduction procedure to access damage accumulation. An input-output non-parametric procedure based on ultrasonic pulse propagation. and a non-linear analyser were chosen to portray the unstable behaviour of brittle rock material under stat... https://www.chiggate.com/color-charm-050-cooling-violet-supply/