Roentgen (unit) absorbed dose in a wide range of matter. When measuring absorbed dose in a human due to external exposure, the SI unit the gray, or the related non-SI rad are used. From these can be developed the dose equivalents to consider biological effects from differing radiation types and target materials. These are equivalent dose, and effective dose for which the SI unit sievert or the non-SI rem are used. The following table shows radiation quantities in SI and non-SI units: Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays
Wilhelm Feldberg of the Royal Society in 1947 and made a Commander of the Order of the British Empire in 1963. Wilhelm Feldberg assisted many research workers who came to England as a part of their Commonwealth Medical Fellowship and Wellcome Research Fellowship. Under this Fellowships, Professor PN Saxena and Prof. KP Gupta of the Department of Pharmacology, Jawaharlal Nehru Medical College, Aligarh Muslim University, during the 1970s got many papers published together with Wilhelm Feldberg while their vocation at National Institute for Medical Research, Mill Hill. Feldberg's career was ended in 1990 when two animal rights activists gained access to his