Hardness Hardness Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood). Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, there are different measurements of hardness: "scratch hardness", "indentation hardness", and "rebound hardness". Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. There are three
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