Władysław I the Elbow-high of Kujawy, however, as he had two older half-brothers from Casimir’s second marriage to Constance of Wrocław: Leszek II the Black ("Leszek Czarny") and Ziemomysł. He was named after his uncle, his mother's brother Władysław, Duke of Opole. Already in contemporary sources he was nicknamed ""Łokietek"", a diminutive of the word "łokieć". It translates as "elbow" or "ell" – a medieval unit of measure similar to a cubit, as in "elbow-high". The origin of this nickname, as resulting from Władysław’s short stature, was explained only in the 15th century by historian Jan Dlugosz. In 1267, when Władysław the Elbow-high was
Probe tip small tips in nanoscale due to resolution limitation of the optical microscopy. In electron field emission current measurement method, a high voltage is applied between tip and another electrode followed by measuring field emission current employing Fowler-Nordheim curves formula_6. Large fields-emission current measurements may indicate that the tip is sharp and low field-emission current indicates that the tip is blunt, molten or mechanically damaged. A minimum voltage is essential to facilitate the release of electrons from the surface of tip which in turn indirectly is used to obtain the tip curvature. The downside of this method to the several advantages