Factors for Ionizing Radiation

Conversion Factors for Enei Units, 1-39 Conversion Factors for Ionizing Radiation,... 

Two important factors in initiating graft copolymerization reactions of vinyl monomers with activated cellulose are (1) the lifetime of the free radical sites and (2) the accessibility of the free radical sites to the monomers. For ceric ion initiation or hydroxyl radical initiation the lifetimes of the free radicals on the cellulose molecule were short (5, 19) therefore, the monomer should be present when the free radicals were formed. For ionizing radiation both short lived and long lived (trapped) free radicals were formed (22, 26, 44). Consequently, the activation reaction and the copolymerization reaction could either be conducted... 

Other factors associated with the risk of NMSC include exposure to ionizing radiation and arsenic, which is connected with BCC. Chemical carcinogens that give rise to NMSC include industrial hydrocarbons that are found in coal tars, soot, asphalt, paraffin waxes, and tobacco.21 Exposure to the human papilloma virus (HPV-6, -11, -16, and -18) has been linked to SCC.31 Lastly, a personal history of previous melanoma is a risk factor for developing another primary melanoma. 

Quality Factor (Q)—The linear-energy-transfer-dependent factor by which absorbed doses are multiplied to obtain (for radiation protection purposes) a quantity that expresses - on a common scale for all ionizing radiation - the approximate biological effectiveness of the absorbed dose. 

Dose equivalent or rem is a special radiation protection quantity that is used, for administrative and radiation safety purposes only, to express the absorbed dose in a manner which considers the difference in biological effectiveness of various kinds of ionizing radiation. The ICRU has defined the dose equivalent, H, as the product of the absorbed dose, D, and the quality factor, Q, at the point of interest in biological tissue. This relationship is expressed as H = D x Q. The dose equivalent concept is applicable only to doses that are not great enough to produce biomedical effects. 

The surface epithelial cells of the small intestine are renewed rapidly and regularly. It takes about two days for the cells of the duodenum to be renewed completely. As a result of its rapid renewal rate, the intestinal epithelium is susceptible to various factors that may influence proliferation. Exposure of the intestine to ionizing radiation and cytotoxic drugs (such as folic acid antagonists and colchicine) reduces the cell renewal rate. 

Table 3 gives an overview of the environmental impact categories that are taken into account in the environmental impact assessment according to the baseline method that is recommended in the Dutch LCA Handbook [1], The characterization for toxicity is based on factors derived by the Usetox model [12], The impact categories depletion of water and ionizing radiation are not taken into account because reliable characterization factors are not available. 

Radiation weighting factors for various types of ionizing radiations... 

Table 32.2 Radiation Weighting Factors for Various Types of Ionizing Radiations...

At lower column densities, one is looking at systems where only a small fraction of the hydrogen is neutral metal lines (e.g. C il-iv, Si Il-iv) are weak and quantitative abundance estimates require an understanding of the ionizing radiation field, which may involve uncertainties of a factor of 3 or more the O VI doublet at AA 1032,1037 A, an important diagnostic, suffers from obscuration by the Ly-a forest. Existing results show a correlation with column density, with < [O/H] > — 1.5 for JV(H I) > 1015 cm-2 and-----2.5 for 10145 < /V(H I) < 1015 cm-2, perhaps reflect-... 

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