Uranium radiation

Although the nucleus of the uranium atom is relatively stable, it is radioactive, and will remain that way for many years. The half-life of U-238 is over 4.5 billion years the half-life of U-235 is over 700 million years. (Half-life refers to the amount of time it takes for one half of the radioactive material to undergo radioactive decay, turning into a more stable atom.) Because of uranium radiation, and to a lesser extent other radioactive elements such as radium and radon, uranium mineral deposits emit a finite quantity of radiation that require precautions to protect workers at the mining site. Gamma radiation is the... 

Rutherford E (1899) Uranium radiation and the electrical conduction produced by it. Philos Mag 47 109-... 

Pais, A. Inward Bound, Oxford University Press New York, 1986 p 113. Rutherford, E. Uranium radiation and the electrical conduction produced by it. Philos. Mag. 1899, 47, 109-163 http //www.chemteam.info/Chem-History/Rutherford-Alpha Beta.html. 

Measurement of radioactiviry, as an analytical tool became possible after the discoveries of A.H.Becquerel(uranium radiation 1896), Pi re Marie Curie (polonium radium in 1898), Sir E. Rutherford (identification of Becquerel rays as consisting of alpha-, beta and gamma-particles) and of F.Soddy(phenomenon of nuclear disintegration, in 1902)... 

The basic unit of radioactivity is the curie, Ci. One curie is the amount of radioactive material that emits particles at a rate of 3.7 X 1010 disintegrations per second (dps), or 2.2 X 1012 min-1 (dpm). Amounts that large are seldom used in experimentation, so subdivisions are convenient. The milli-curie (mCi, 2.2 X 109 min-1) and microcurie (yu,Ci, 2.2 X 106 min-1) are standard units for radioactive measurements (see Table 6.2). The radioactivity unit of the meter-kilogram-seconds (MKS) system is the becquerel (Bq). A becquerel, named in honor of Antoine Becquerel, who studied uranium radiation, represents one disintegration per second. The two systems of measurement are related by the definition 1 curie = 3.70 X 1010 becquerels. Since the becquerel is such a small unit, radioactive units are sometimes reported in MBq (mega, 106) or TBq (tera, 1012). Both unit systems are in common use today, and radioisotopes received through commercial sources are labeled in curies and bequerels. 

Table 2-2. Levels of Significant Exposure to Uranium - Radiation Toxicity - inhalation... 

Henry Becquerel was born in Paris in 1852. Both his father and his grandfather were well-known scientists and university professors. Henry studied at the Ecole Polytechnique and started his career there as an assistant. In 1891 he inherited his father s chair in physics at the Conservatoire des Arts et Metiers, and in 1895 became a professor of the Ecole Polytechnique too. He was a member of the French Academy of Science. His discovery in 1896 of uranium radiation was epoch-making, it was in fact the overture of the atomic age. For this discovery he won the Nobel Prize in Physics in 1903. The unit of radioactive radiation (1 disintegration/s), the becquerel, bears his name. He was successful in other fields of physics too. He dealt much with spectroscopy. He died in Le Croisis in 1908 (Ranc 1946). 

EPA. (2006). Uranium-radiation protection, http //www.epa.gov/radiation/radionuclides/ uranium.html (accessed August 3, 2014). 

Kehagia, K., Bratakos, S., Kolovou, M. et al. (2010). Hair analysis as an indicator of exposure to uranium, Radiat. Prot. Dosimetry 144,423 26. 

Calcium-phosphate-type sensors are essentially unaffected by large doses of Co-gamma radiation (11) and thus the corresponding uranyl phosphate, and possibly neutral carrier types, should be immune to the very modest doses of internally generated uranium radiation. 

In 1889, still very young, Henri Becquerel was elected a member of the Academie des Sciences de France. His membership there came to be important in coimection with the discovery of uranium radiation. The Becquerel family, Henri s father Alexandre-Edmond and also his grandfather Antoine-Edmond, had been passionately interested in luminescence. Henri himself had, for his father s investigations, prepared beautiful crystals of potassium uranyl sulfate, a substance with fluorescing properties. In his earliest scientific work he also was concerned with the phenomenon of phosphorescence and with the absorption of light by crystals (the subject of his doctoral thesis). 

Becquerel made an additional important discovery about his uranium radiation. A gold leaf electroscope was charged and the leaves separated. Different substances, placed in its vicinity, had no effect on the position of the gold leaves. Under the influence of a uranium salt, the leaves however fell down. The gold leaf electroscope is not an instrument of precision, nor is it very sensitive. The experiment however demonstrated that uranium radiation cooperates with electricity. This property made it possible for Pierre Curie to develop equipment for quantitative radiation measurement. 

In France, Becquerel was almost alone in the research on uranium radiation. At the University of Sorbonne, a young Polish woman, Marie Sklodowska, studied and worked. She had been married for one year to a Frenchman, the physicist Pierre Curie. Professor Becquerel had observed her. She seemed to be clever and skilled in experimental work. He told her about his findings and put a straight question to her. Would she work with uranium radiation The answer was yes. 

In 1894, Marie met the eight years older Pierre. They became friends and colleagues in materials research. And still more. The year after they met, they married. Marie s father arrived from Warsaw for the simple wedding celebration. After the wedding they continued their assignments. Marie completed her studies and did some work at the Scale Industridle. One day Professor Henri Becquerel paid a visit to Madame Curie and asked if she would examine pitchblende. Marie and her husband Pierre realized that research on uranium radiation could be an excellent field for... 

Hahn, O., Strassmann, F. About the evidence and the behavior in uranium radiation using neutron occuring earth alkaloid metals. Naturwissenschaften 27, 11-15 (1939)... 

Fukuda, S., Ikeda, M., Chiba, M., et al., 2006b. Clinical diagnostic indicators of renal and bone damage in rats intramuscularly injected with depleted uranium. Radiat. Prot. Dosim. 118, 307-314. 

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