Roentgen (unit) One roentgen deposits of absorbed dose in dry air, or in soft tissue. One roentgen of X-rays may deposit anywhere from in bone depending on the beam energy. This tissue-dependent conversion from kerma to absorbed dose is called the F-factor in radiotherapy contexts. The conversion depends on the ionizing energy of a reference medium, which is ambiguous in the latest NIST definition. The roentgen has its roots in the Villard unit defined in 1908 by the American Roentgen Ray Society as "the quantity of radiation which liberates by ionisation one esu of electricity per cm of air under normal conditions
Wilhelm Stier - 1999, Professor at the Techical University of Graz, Austria Wilhelm Stier - Familytree - Family member. Wilhelm Stier Wilhelm Stier (born May 8, 1799 in Błonie near Warsaw, died September 19, 1856 in Schöneberg, full name: Friedrich Ludwig Wilhelm Stier) was a German architect and university teacher at the Berlin Bauakademie. Wilhelm Stier was born the son of Christiane Eleonora Stiers 1766 - & Friedrich Ludewik Stier 1765 - 1815 a German postmaster & taxman in the then Prussian province of South Prussia & then Wilhelms family moved to Silesia. Wilhelm Stier was Grand son to Medical Officer /