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 Carlo Janka Carlo Janka (born 15 October 1986) is an alpine ski racer from Switzerland. Born in Obersaxen, in the canton of Graubünden, he had the winter sports facilities right in front of his home. Janka has won gold medals at both the Winter Olympics and the World Championships, as well as one World Cup overall title, one discipline title and also, one unofficial alpine combined title. In 2013, Janka set a World Cup speed record in the downhill part of the super combined event in Wengen, Switzerland. He reached a maximum speed of on the "Haneggschuss", the fastest section