Science.gov (United States)

The GRO observation (Hartman et al., 1992) of a very strong flux of gamma rays with an energy index

Wastenet

...] 2010, Volume 11, Issue 1 3-27 The European Economic and Monetary Union and Labour Market Reform by Elzbieta Bednarek-Sekunda & Richard Jong-A-Pin & Jakob de Haan [Downloadable!] 29-59 Educational Inequality in the EU: The Effectiveness of the National Education Policy by Raphaela Schlicht & Isabelle Stadelmann-Steffen & Markus Freitag [Downloadable!] 61-87 Opinion Polarization and Inter-Party Competition on Europe by Ian Down & Carole J. Wilson [Downloadable!] 89-117 EU Issue Voting: Asset or Liability?: How European Integration Affects Parties' Electoral Fortunes ...

International Nuclear Information System (INIS)

Perforated thermoplastic masks are used to provide patients immobilization. This procedure inserts a material in the path of the radiation beam, that attenuates and modifies the beam fluence and flatness. The present study evaluates the increase in skin dose as a result of using thermoplastic masks. Relative doses were measured on the surface of a solid water phantom, in the presence and absence of masks. These masks were stretched according to deformation patterns observed in clinical routine. The measurements were obtained with a plane-parallel chamber (Markus type 23343) and radiochromic film (EBT Gafchromic) for 6MV X-rays from a linear accelerator, and for a radiation beam from a cobalt therapy unit. The results showed that thermoplastic masks, whose thickness varied between 2 and 3 mm, increased the dose on the surface by a factor of 3. Due to the variations in the skin dose distribution, clinical procedures were suggested to minimize radiobiological damages ...