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
Janka Kulcsár Janka Kulcsár Janka Kulcsár (born 8 April 1985) is a Hungarian pianist and répétiteur, and a founding member of the Moltopera Company. Janka Kulcsár was born on 8 April 1985 in Budapest. Kulcsár entered the Béla Bartók Conservatory at the age of fourteen. She participated frequently in summer courses during this period, like the International Music Camp in Balassagyarmat. At the age of eighteen she had already been a student of the Franz Liszt Academy of Music, coached by Lehel Both, at the age of twenty she won the 1st prize of the National Piano Competition for University Students. In