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
David Roentgen Gotha, exhibited at Callenberg Castle in Coburg, north Bavaria. In 2012 Wolfam Koepp of the Metropolitan Museum of Art discovered a particular type of Roentgen table with removable legs for easier transport. Was this table the earliest form of flatpack? A team from the Victoria and Albert Museum investigated further and confirmed Koepp's process and conclusions in March 2014, shedding new light on the inventor of flat-pack / ready-to-assemble furniture. Until then, Gillis Lundgren held that title from 1951 for IKEA. Its blame has now been traced back 200 years before the pretender. David Roentgen not only mastered intrigue but