Radiation local effects

The temperature for methane and butane calculated with the isothermal model is a factor 1.4 times greater than the average temperature measured by Lihou and Maund (1982) in their small-scale tests, although higher local maximum temperatures were measured. In this model, combustion is stoichiometric, thus leading to very high fireball temperatures which, in turn, lead to high radiation emissions. Effective surface emissions measured experimentally were one-half the value calculated from this model, because combustion is not stoichiometric and emissivity is less than unity. 

Natural and coUisional broadening are homogeneous processes because aU radiators experience the same local effects. These produce, for both gases and Hquids, a Lorentzianline shape, with Av (fwhm) =, where 1 is the effective lifetime of a radiator s unintermpted osciUation period. In gases,... 

Another local effect, in this case due to surface cover, is the urban heat island. Rapid heating of urban pavements and buildings occurs during the daytime because of the high absorbance of constructed surfaces and the absence of cooling from evapotranspiration. At night, rural areas cool more effectively than urban areas because of the relatively unobstructed exposure of the land surface, in contrast to the impediment to heat radiation presented by tall, closely spaced buildings. As a result, daily minimum and maximum... 

The decrease in catalytic activity eliminated a local effect of radiation-produced defects as an explanation, since the production of more sites... 

Besides exerting local effects in the skin, ultraviolet radiation may, through the production of circulating mediators, also cause systemic immunosuppression. This could be an explanation of the suppression of autoimmune conditions, such as multiple sclerosis and diabetes mellitus type 1, noted to occur less frequently in those countries with abundant sun. 

For the analysis of the macroscopic heat flow through heterogeneous media, the local volume-averaged (or effective) properties such as the effective thermal conductivity k) = k, are used. These local effective properties such as the heat capacity (pcp), thermal conductivity (k), and radiation absorption and scattering coefficients (a ) and (a,) need to be arrived at from the application of the first principles to the volume over which these local properties are averaged, that is, the representative elementary volume. 

The danger from radioactive substances is mainly due to the detrimental effects of the emitted ionizing radiation however, there are also toxic effects at the level of biochemical reactions. The most iihportant effects of radioactive radiation from accumulated radionuclides are manifested at a much later date in the form of genetic consequences. There are also local effects, since the radionucfides are frequently accumulated in a certain critical organ ( °Sr in bones, Cs in muscles, etc.). Thus, the local radiation dose can exceed by a factor as high as 50 the mean whole-body dose. In many cases, tumour growth may be induced. 

Different modes of damage are possible as a result of the mechanical tests. It is necessary to consider the results of these modes for any analytical assessment to demonstrate compliance with the applicable requirements. The fracture of a critical component or the breach of the containment system may allow the escape of the radioactive material. Deformation may impair the function of radiation or thermal shields and may alter the configuration of fissile material and it should be reflected in the assumptions and predictions in the criticality assessment. Local damage to shielding may, as a result of the subsequent thermal test, give rise to deterioration of both thermal and radiation protection. Consequently, investigations should include stress, strain, instability and local effect for all attitudes of drop where symmetry does not prevail. 

PIEs may have an impact on safety systems by means of local effects, such as direct mechanical contact or jet impingement, as well as global effects, such as flooding, increases in humidity, increases in temperature, asphyxiant effects and higher radiation levels. These possible effects should be analysed. 

Except for chemicals produced in the environment by radiation, such as HNO3 and H2O2, which have a secondary effect on corrosion, or formation of localized displacement spikes during radiation, the effect of radiation may be expected to parallel that of cold work. That is, metals for which the corrosion rate is controlled by oxygen diffusion should suffer no marked change in rate after irradiation. In acids, on the other hand, irradiated steel (but not pure iron) would presumably have a greater increase in rate than would irradiated nickel, which is less sensitive to cold working. 

The formed dose-response functions were incorporated into a Computational Fluid Dynamics (CFD) software program, simulating the environment of a sample within a Phoenix-exposed IP/DP (Instrument Panel/Door Panel box) box, based on sun position and weather conditions, including radiation interactions. Observed local effects as well as the general ageing advance of PP hats are compared with respect to simulation and experiment. 

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