Barcol hardness test the Barcol impressor was developed by Walter Colman as a hand-held, portable means of assessing the hardness of a material during World War II. The United States Army Air Corps required a hand-held method of checking the hardness of rivets due to concerns that aircraft could be sabotaged by replacing normal rivets with soft lead or wooden ones which would fail during flight. The impressor operates when the tip is pressed against the material in question. The hardness of the material determines how far the tip indents and this is transferred by a tension spring and lever to be read
Carlo Janka Cup overall title. He clinched the title by winning the downhill and giant slalom, which left his nearest opponent, Benjamin Raich, 106 points back with one race remaining, an insurmountable margin. In October 2010, Janka was awarded the Skieur d'Or Award by members of the International Association of Ski Journalists for his performances during the previous season, thereby becoming the first Swiss male skier to receive the honour since Pirmin Zurbriggen won it back in 1990. Following the 2011 World Championships, Janka underwent surgery due to increased symptoms from heart arrhythmias. A radio frequency catheter intervention was done on 23