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 Krause Wilhelm Krause Johann Friedrich Wilhelm Krause (July 12, 1833 – February 4, 1910) was a German anatomist born in Hanover. He was the son of anatomist Karl Friedrich Theodor Krause (1797-1868). In 1854 he earned his medical doctorate, and later (1860) became an associate professor at the University of Göttingen. In 1892 he was appointed head of the Anatomical Institute Laboratory in Berlin. Krause is known for the discovery and description of mechanoreceptors that were to become known as "Krause's corpuscles", sometimes referred to as "Krause's end-bulbs". His name is also associated with: Krause is also remembered for pioneer research