Effect of Irradiation

Fig. 14. Data illustrating effect of 7-irradiation on the methanation of carbon dioxide over supported Ru catalysts comprising ruthenium on alumina (Ru/Al) or ruthenium in molecular sieve (Ru/M). Effects of 7-irradiation at the indicated temperature on the growth of methane product observed from a continuous flow of C02 in a H2 carrier gas over (i) Ru/M and (ii) Ru/Al. Note the growth in methane yields from C02—H2 reaction at different temperatures as a function of 7 dose and its decay with time subsequent to removal of the catalyst from the 7-source.

Demertzis, P.G. Franz, R. Welle, F. The effects of 7-irradiation on compositional changes in plastic packaging films. Packag. Technol. Sd. 1999,12, 119-130. 

Polyethylene and polystyrene are examples of plastics subject to environmental stress cracking. Crack resistance tests have shown that surfactants, alcohols, organic acids, vegetable and mineral oils, and ethers provide an active environment for stress cracking of polyethylene. Table 6 lists typical sterile devices and plastic materials used to fabricate them, while Tables 7-9 list the potential effects of sterilization processes on polymeric materials. The effect of gamma irradiation on elastomeric closures has been studied by the Parenteral Drug Association [15]. 

In a related study by the same authors, the effect of microwave irradiation on car-bodiimide-mediated esterifications on a solid support was investigated, employing benzoic acid [29]. The carboxylic acid was activated using N,N -diisopropylcarbodi-imide (DIC) through the O-acyl isourea or the symmetrical anhydride protocol (Scheme 7.9). The isourea protocol was carried out in a dichloromethane/N,N-di-methylformamide mixture in sealed vessels, whereas the anhydride reactions were carried out in l-methyl-2-pyrrolidinone (NMP) at atmospheric pressure. 

The readily prepared immobilized phosphoramidite could be used to efficiently synthesize oligodeoxyribonucleotides with modified thymidine residues. Whereas the effect of microwave irradiation on the deprotection by exposing the strand to tet-rakis-triphenylphosphine palladium(O) and diethylammonium bicarbonate was only small using dichloromethane as solvent, complete removal of the alloc group was achieved in N,N-dimethylformamide within 10 min at 80 °C (Scheme 7.30). After the reaction, the solid-supported product was washed with N,N-dimethylformamide and dichloromethane and dried, before being subjected to acylation. The coupling... 

The main effect of MW irradiation on the graphite- and charcoal-supported catalysts is to reduce the average temperature required for the reaction to occur. The authors believe this is the result of hot spots formed within the catalyst bed (Sect. 7.4.2). Graphite-supported catalysts, moreover, seem to be more selective than the equivalent charcoal-supported catalysts, especially under the action of MW irradiation - 83.6-97.7% compared with 68.4-86.3%. This might be because of the hydrophobic nature of the graphite which directs the reaction away from the production of water by dehydration of the alcohol. 

Miao M, Hawkins SC, Cai Y, Gengenbach TR, Knott R, Huynh CP. Effect of gamma-irradiation on the mechanical properties of carbon nanotube yarns. Carbon. 2011 Nov 49(14) 4940-7. 

Yahagi, K., K. Shinohara, and K. Mori y ray induced conductivity in polyethylene, effect of pre-irradiation and crystallinity. Rep. Prog. Polymer Phys., Japan 7, 313 (1964). 

Noyan, S., Kahveci, Z., Cavusoglu, I., Minbay, F. Z., Sunay, F. B., and Sirmali, S. A. 2000. Effects of microwave irradiation and chemical fixation on the localization of perisinusoidal cells in rat liver by gold impregnation. 7. Microsc. 797 101-106. 

Fig. 10. Effect of y-irradiation on the MW of substituted polyacetylenes,7) in air, 60 °C, film ( — 0.1 mm), total dose 40 Mrad, dose rate 2.2 Mrad h ...

Effects of gamma irradiation on elastomeric closures, technical report no. 16. PDA. J. Parent. Sci. TechnoL 1992, 52, S1-S13. 

Arising from the decomposition of C -labeled carbohydrates are an enormous variety of products. For example, when a sample of D-glucose-C (about 6 mg., having a specific activity of about 14.44 mC. per millimole) was stored as a freeze-dried sample in the dark for 26 months, a 14.5% decomposition of the D-glucose occurred and, by use of two-dimensional paper chromatography-paper electrophoresis, the presence of 37 constituents was revealed. The greater complexity of this system in comparison with that of 7-irradiated solutions of D-glucose supports the view that direct-action effects supplement the decomposition caused by secondary-radiation effects, which are entirely responsible for the decomposition when dilute solutions are irradiated. 

Studies of the variation in radical concentration with incre in temperature shows the very distinctive riw in radical concentration around Tg, when the radicals are produced by mechanical d adation. This effect is clearh visible in Fig. 44 and is referred to as the anomalous effect or anomalous decay. It is not observed from samples in which the radicals have been produced by irradiation. Figure 45 shows the decay curves obtained by Sohma etaL ° from polypropylene, where the radicals have been produced by mechanical degradation or 7-irradiation. The peak in radical concentration is absent in the case of 7-irradiated samples. 

Jach [59. 60] studied the effect of reactor irradiation on the thermal decomposition of colloidal a-lcad azide (average particle size 7 pm), irradiated for 35 hr in a flux (fast plus slow neutrons) of approximately 7-8 X lO n/cm /sec and a... 

Steady-state 7-irradiation of any explosive has not been known to initiate a detonation. The effect of such irradiation appears to result in slow decomposition with, in the case of primary explosives, a deterioration in the functional properties of the samples. 

Figure 1. Effect of gamma irradiation on the oxygencarrying capacity of different concentrations of oxygenated hemocyanins in phosphate buffer at pH 7.0. The oxygenation reaction time was 10 minutes and the deoxygenation reaction time was 30 minutes...

Thomas et al. [1986] studied the effect of gamma irradiation (1,10,100 and 500 kGy) on PVC/TPE = 100 0, 75 25, 50 50, 25 75 and 0 100 blends (Table 11.9). As TPE a thermoplastic, elastomeric polyether-ester block copolymer of 1,4-butane-diol-polybutylene and glycol-terephthalic acid copolymer (ElytreF ), was used. The blends were prepared in an internal cam-type mixer at 80 rpm, 180°C, mixing time 7 min. TPE was added first,... 

The major attention is given to the conqjensated GaAs superlattices with the layer thickness of 40 nm and concentration of donors and acceptors of 10 cm. The superlattice named No. 4i contains i-layers n-i-p-I stracture) and No. 4 means no i-layers n-p-n-p stmcture). Both structures belong to the long-period doping superlattices and their photoluminescence properties were measured in a wide temperature range. Pronounced effects of a-irradiation were observed [7]. 

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