Effects of Radiation doses

Figure 8 Effect of radiation dose on copolymerization of acrylamide with DAEA-HCl. O = q(%) = [tj].

Figure 6 Effect of radiation dose on the graft yield (%) of grafted cotton linters.

Table IV. Effect of Radiation Dose on Pouch Sealability...

It should be noted that there is intense controversy as to the health effects of radiation doses below about 100 mSv per year. This estimate of 15,000 annual cancer deaths from indoor radon, as well as estimates of tens of thousands of eventual cancer deaths from Chernobyl exposures, is obtained by applying the linearity hypothesis. This hypothesis has been adopted by most regulatory agencies but is strongly contested by some scientists who believe it overestimates the effects of radiation at low dose levels. Of course, if calculations based on this hypothesis overestimate the deaths from indoor radon, they also overestimate the effects of potential radiation from a waste repository. 

Figure 5. Effect of radiation dose rate on grafting of 77-23 PVC-styrene using heat treatment...

Figure 2. Effect of radiation dose on internal ethylene concentration in McIntosh apples...

FIG U RE 8.8 Effect of radiation dose on the distribution ratios of various actinides from 0.5 M (—) or 5 M HN03 (-) by 1 M DMDBHDEMAin terr-butylbenzene. (Redrawn from Thiollet, G., Musikas, C., Solvent Extr. IonExch. 7(5) 813-827, 1989. With permission.)... 

Effect of Radiation Dose on Micellar Properties. Figure 1 shows the concentration dependence of the micellar diffusion coefficient at 40° as determined by quasi-elastic light scattering (QELS) for solutions subjected to radiation doses of up to 4.56 Mrad. Limiting diffusion coefficients, D0>were obtained by extrapolation of data for dilute solutions (<0.05%) to zero concentration, the critical micelle concentration (CMC) being negligibly low for this poloxamer ( 1 ). 

PTFE micropowders (also referred to as fluoroadditives) are homopolymers of tet-rafluoroethylene with molecular weight significantly lower than normal PTFE (see Table 7.6). They are prepared mainly by irradiation of PTFE (often of PTFE scrap) by high-energy electron beam [104]. The effect of radiation dose is illustrated by... 

A wealth of new information about radiation exposure over the past decade prompted the revision of the BSS. First and foremost, a study of the biological effects of radiation doses received by the survivors of the atomic bombing of Hiroshima and Nagasaki suggested that exposure to low-level radiation was more likely to cause harm than previously estimated. Other developments—notably the nuclear accident at Three Mile Island in 1979 and that at Chernobyl in 1986, with its unprecedented transboundary contamination—had a profound effect on the public perception of the potential danger from radiation exposure. There were serious accidents with radiation sources used in medicine and industry in Mexico, Brazil, El Salvador and other countries. In addition, more has been discovered about natural radiation—such as household radon—as a cause of concern for health. Finally, natural radiation exposures of workers such as miners, who were not thought of as radiation workers, were discovered to be much higher than had been realised. 

FIGURE 31.14 Effect of radiation dose (200 kGy) on the subsequent decrease in the pertraction as a function of time. 

Aqueous emulsions of styrene, methyl methacrylate, methyl acrylate, and ethyl acrylate were polymerized with y-radiation from a Co source in the presence of sodium dodecyl sulfate or sodium laurate. The continuous measurement of conversion and reaction rate was carried out dilato-metrically. The acrylates polymerized fastest and the over-all polymerization rate increased as follows styrene < methyl methacrylate < ethyl acrylate methyl acrylate. The effects of radiation dose, temperature, and original monomer and emulsifier concentrations were studied with respect to the following factors properties of polymer dispersions, number and size of polymer particles, viscometrically determined molecular weights, monomer-water ratio, and kinetic constants. 

Iodine deficiency may also have had a promoting effect on thyroid cancer development after the Chernobyl accident (Shakhtarin et al, 2003). As a result of this accident, there may have been a combined effect of radiation dose and iodine deficiency in which iodine deficiency doubled the excess relative risk for cancer per Gray (Gy). 

In a study by Carpenter and co-workers, three polymers (I, III, and IV) were made using TMP to prepare the respective polymeric initiators, as described in Section 3.23P In an effort to produce compliant monofilaments, these polymers were extruded to monofilaments and processed under slightly different conditions from those used in preparing their counterparts in section 3.2.3. One of the polymers (I) was used to prepare a second set of monofilaments for studying the effect of radiation dose, under a typical radiochemical sterilization process (RC-S) on their in vitro breaking strength retention (BSR). 

Effect of Radiation Dose on Recoil Labeled Species Tritium and Cyclopropane"... 

The effect of radiation dose and the hydrolysis conditions on the chemical structure of electron irradiated PTFE was studied. Irradiation produced acid fluoride (COF) groups and, under ambient conditions, these hydrolysed with atmospheric humidity to form free and associated carboxylic acid (COOH) groups. The concentrations of these groups were different in the near-surface and bulk regions. The formation of carboxylic groups in different states of association depended on the hydrolysis conditions (146). 

Baccaro et al. have investigated the ehemical interactions between N375 carbon black and NR matrix under eleetron beam irradiations. In their ESR studies, effects of radiation dose on free radical concentration were evaluated by applying 191 kGy, 499.5 kGy and 1 MGy irradiation doses to the compounds at 2 kGy/h dose rate. The results are shown in Figure 25.24(a). The shapes of the ESR spectra remain unchanged with different radiation doses, whereas intensity of the derivative peaks change with the radiation doses. It is assumed that the radiation-induced free radical concentration may be proportional to the peak-to-peak intensity signal. The intensity of the spectra lines increases up to 499.5 kGy and then decreases at 1 MGy radiation dose. The... 

Khalid, M., Ismail, A.F., Ratnam, C.T., Earidah, Y., Rashmi, W., A1 Khatib, M.F. Effect of radiation dose on the properties of natural mbber nanocomposite. Radiat Phys. Chem. 79, 1279-1285 (2010)... 

Fig.1. The effect of radiation dose on the mechanical properties of a polychloroprene polymer. E denotes elongation at break, H represents Shore D hardness, and R represents the tensile strength [18]...

Table 11.11(a) Effect of radiation dose on the intrinsic viscosity of polyoxyethylene, molecular weight 600000, at 0.5 % and 1 % concentration... 

Effect of radiation dose on tensile strength Elongation at break Modulus for optimisation of radiation dose. 

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