The Behavior of Actinide Containing Glasses During Gammirar Adiation in a Saturated Tuff Environment

1984 ◽  
Vol 44 ◽  
Author(s):  
John K. Bates ◽  
Virginia M. Oversby

AbstractThe influence of gamma irradiation on the reaction of actinide doped SRL 165 and PNL 76–68 glasses in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The reaction, and subsequent actinide release, of both glasses depends on the dynamic interaction between radiolysis effects which cause the solution pH to become more acidic and glass reaction which drives the pH more basic. The use of large gamma irradiation dose rates to accelerate reactions that would occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons are made between the present results and data obtained by reacting the same or similar glasses using MCC-1 and NNWSI rock cup procedures.

1990 ◽  
Vol 53 (4) ◽  
pp. 329-331 ◽  
Author(s):  
GENE E. LESTER ◽  
DAN A. WOLFENBARGER

Percent electrolyte leakage, a measure of membrane integrity, proved to be a good predictor (R2 = 0.99) of cobalt-60 gamma irradiation dose injury on mid-season ‘Ruby Red’ grapefruit Citrus paradisi (Macf.) flavedo tissue (peel). Percent electrolyte leakage on grapefruit peel following a dose-rate of 250 grays/1.0, 2.5, 5.0, and 25.0 min decreased as grays/min (dose-rate) decreased. Total phenols, a biochemical response to irradiation following 250 grays/1.0, 2.5, 5.0, and 25.0 min also decreased as dose-rate decreased, demonstrating that injury to grapefruit peel diminished as 250 grays of gamma irradiation/rate declined. Comparisons of 10 and 20 grays of cobalt-60 gamma irradiation showed that a dose-rate of 10 grays/0.25 min to naked 8-d old Mexican fruit fly Anastrepha ludens (Loew) larvae caused a 90% reduction of adult emergence. Whereas, at 20 grays the reduction was greater than 99% with dose-rates of 20 grays/0.25, 0.5, 1.0, or 100 min. These data show that a gamma irradiation dose capable of reducing fly emergence by >99% will maintain an inhibitory effect even at relatively lower dose-rates. Therefore, once a quarantine security treatment for Mexican fruit fly is established, a lower dose-rate will reduce adult emergence and should impart little damage to grapefruit peel tissue.


2021 ◽  
Vol 12 (3) ◽  
pp. 334-339
Author(s):  
Lamiye YILDIZ

The present’s experimental data on the influence of the venom of the honey bee on the life span of experimental animals irradiated with small doses of gamma radiation on physiological and pharmacological action venom of the honey bee Apis mellifera Caucasica. The aim of the studies was to study the radioprotective effect of the pre-introduced venom Apis mellifera Caucasica with a single gamma irradiation of 60Co mice at doses of 1.3, 5, 7, 10 Gy at irradiation dose rates of 1 Gr / min. Injection of venom followed by gamma irradiation of 60Co at a dose of D = 1, 3, 5 and 7 Gy at an irradiation dose rate of 1 Gy / min increased the life span of the experimental groups of mice ranging from 45% to 56 % and from 52% to 67%, respectively. An increase in the lifespan of experimental rats exposed to radiation with the preliminary introduction of the venom of the honey bee.


2007 ◽  
Vol 1038 ◽  
Author(s):  
Nathan J Withers ◽  
Krishnaprasad Sankar ◽  
Brian A. Akins ◽  
Tosifa A. Memon ◽  
Jiangjiang Gu ◽  
...  

AbstractThe effects of 137Cs gamma irradiation on photoluminescence properties, such as spectra, light output, and lifetime, of several types of colloidal nanocrystals have been investigated. Irradiation-induced damage testing was performed on CdSe/ZnS, LaF3:Eu, LaF3:Ce, ZnO, and PbI2 nanocrystals synthesized on a Schlenk line using appropriate solvents and precursors. Optical degradation of the nanocrystals was evaluated based on the measured dependence of their photoluminescence intensity on the irradiation dose. Radiation hardness varies significantly between various nanocrystalline material systems.


Silicon ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 2499-2504 ◽  
Author(s):  
M. N. Mirzayev ◽  
S. H. Jabarov ◽  
E. B. Asgerov ◽  
R. N. Mehdiyeva ◽  
T. T. Thabethe ◽  
...  

1992 ◽  
Vol 294 ◽  
Author(s):  
X. Feng ◽  
J. K. Bates ◽  
C. R. Bradley ◽  
E. C. Buck

ABSTRACTStatic tests at SA/V (ratio of surface area of glass to solution volume) 20,000 m−1 on SRL 200 glass compositions show that, at long test periods, the simulated nuclear waste glass (nonradioactive) leaches faster than the corresponding radioactive glass by a factor of about 40, although comparative tests, done through 560 days, at lower SA/V, 2000 m−1, indicate little difference in the leach behavior of the two types of glasses. The similarity in leach behavior between radioactive and simulated glasses at SAN of 2000 m−1 or lower is also observed for SRL 165/42 and 131/11 compositions. The accelerated glass reaction with the simulated glass 200S is associated with the formation of crystalline phases such as clinoptilolite (or potassium feldspar), and a pH excursion. The radiation field generated by the fully radioactive glass reduces the solution pH. This lower pH, in turn, may retard the onset of increased reaction rate. The radiation field generated by the radioactive glasses does not directly affect the stability of the glass surface alteration layer under those conditions where the radioactive and simulated glasses react at the same rate. These results suggest that the fully radioactive nuclear waste glass 200R may maintain a much lower leach rate than the simulated 200S, if the lower pH in the 200R leachate can be sustained. Meaningful comparison tests between radioactive and simulated nuclear waste glasses should include long-term and high SA/V tests.


2015 ◽  
Vol 5 (4) ◽  
pp. 9-15
Author(s):  
Thanh Long Nguyen ◽  
Quang Luan Le

The mixtures β-glucan extracted from the yeast cell wall were irradiated under gamma rays from a Co-60 source at doses of 100, 200 and 300 kGy in order to prepare water-soluble β-glucan. Yields of the water soluble β-glucan produced are 25.9, 49.1, 66.71%, and their molecular weights (Mw) are 30.5, 24.9 and 10.8 kDa, respectively. There are no any new peak in the IR spectra of the irradiated β-glucan samples, but the intensity ratio between the peaks at wavenumber of 1156 cm-1 (assigned to C-O-C bond) and of 1040 cm-1 (assigned to C-C bond) in glycosidic linkages was reduced with irradiation dose. These results revealed that gamma irradiation did not cause any change in the β-glucan structure except the scissions of glycosidic linkages. In this study, immuno stimulation of the irradiated b-glucan was also investigated for the Swiss mice. After 28 days supplying with the irradiated b-glucan, not only cellular indexes (white blood cell, neutrophils and lymphocytes counts), but also humoral  immunity indexes (IgA and IgM) of the mice significantly increased and the highest effects was obtained for the mice supplied with the oligoβ-glucan prepared by gamma irradiation at 200 kGy. Thus, the water soluble oligoβ-glucan with Mw ~ 24.9 kDa prepared by gamma radiation much stimulated the natural immune system (non-specific immunity) in mice including both the cellular and humoral immunities. Particularly, the irradiated b-glucan is a very promising product for preparation of functional foods aiming at cancer prevention.


2011 ◽  
Vol 80 (2) ◽  
pp. 142-144 ◽  
Author(s):  
Mari Fujimoto ◽  
Mayuko Takeda ◽  
Kouji Okamoto ◽  
Masakazu Furuta

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