Effects of Pre- and Post-Irradiation Temperature Treatments on TL Characteristics and Radiation Induced Sensitisation of Various TL Peaks in LiF-TLD 100

1999 ◽  
Vol 84 (1) ◽  
pp. 175-178 ◽  
Author(s):  
B.C. Bhatt ◽  
S.N. Menon ◽  
R. Mitra
Keyword(s):  
Irradiation Temperature ◽  
Post Irradiation ◽  
Radiation Induced

scholarly journals Radiation-Induced Metabolic Shifts in the Hepatic Parenchyma: Findings from 18F-FDG PET Imaging and Tissue NMR Metabolomics in a Mouse Model for Hepatocellular Carcinoma

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2573
Author(s):  
Yi-Hsiu Chung ◽  
Cheng-Kun Tsai ◽  
Ching-Fang Yu ◽  
Wan-Ling Wang ◽  
Chung-Lin Yang ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Liver Parenchyma ◽  
Metabolic Alterations ◽  
Nmr Metabolomics ◽  
Post Irradiation ◽  
The Third ◽  
Radiation Induced ◽  
18F Fdg ◽  
The Right ◽  
Over Time

Purpose: By taking advantage of 18F-FDG PET imaging and tissue nuclear magnetic resonance (NMR) metabolomics, we examined the dynamic metabolic alterations induced by liver irradiation in a mouse model for hepatocellular carcinoma (HCC). Methods: After orthotopic implantation with the mouse liver cancer BNL cells in the right hepatic lobe, animals were divided into two experimental groups. The first received irradiation (RT) at 15 Gy, while the second (no-RT) did not. Intergroup comparisons over time were performed, in terms of 18F-FDG PET findings, NMR metabolomics results, and the expression of genes involved in inflammation and glucose metabolism. Results: As of day one post-irradiation, mice in the RT group showed an increased 18F-FDG uptake in the right liver parenchyma compared with the no-RT group. However, the difference reached statistical significance only on the third post-irradiation day. NMR metabolomics revealed that glucose concentrations peaked on day one post-irradiation both, in the right and left lobes—the latter reflecting a bystander effect. Increased pyruvate and glutamate levels were also evident in the right liver on the third post-irradiation day. The expression levels of the glucose-6-phosphatase (G6PC) and fructose-1, 6-bisphosphatase 1 (FBP1) genes were down-regulated on the first and third post-irradiation days, respectively. Therefore, liver irradiation was associated with a metabolic shift from an impaired gluconeogenesis to an enhanced glycolysis from the first to the third post-irradiation day. Conclusion: Radiation-induced metabolic alterations in the liver parenchyma occur as early as the first post-irradiation day and show dynamic changes over time.

Gamma-Ray Radiation-Induced Surface Hydrophobic Effects in Invar Alloy

2012 ◽  
Vol 482-484 ◽  
pp. 1585-1591 ◽  
Author(s):  
Cheng Fu Yang ◽  
Wei Wen Wang ◽  
Hsin Hwa Chen ◽  
Wei Tan Sun ◽  
Chi Lin Shiau ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Structural Changes ◽  
Gamma Ray ◽  
Small Deviation ◽  
Contact Angles ◽  
Invar Alloy ◽  
Hydrophobic Effects ◽  
Post Irradiation ◽  
Radiation Induced ◽  
Gamma Ray Irradiation

In this paper, we report a new phenomenon observed in the gamma-ray radiation-induced hydrophobic effects on an Invar surface: When the Invar alloy is subjected to different doses of gamma-ray irradiation, the contact angle increases with the radiation dose. Invar samples with exposed to a higher dose appear more hydrophobic, but this tendency disappears following post-irradiation etching. The contact angles of the irradiated and etched Invar samples can be restored back to a stable value with small deviation after 30 min of annealing at 150°C. X-ray diffraction (XRD) analysis found no crystalline structural changes. High resolution field emission scanning microscope (FE-SEM) analyses showed that irradiation might induce crack-like surfaces which could be removed at higher radiation dose in the following acid etchings. It is believed that the chemical bonds of Invar oxide on the surface were broken by the gamma-ray irradiation, thus raising the likelihood of binding with free ions in the air and resulting in the exclusion of the hydrophilic OH bonds, leaving a hydrophobic post-irradiation Invar surface.

scholarly journals Specific Features of Structural-Phase State and Properties of Reactor Pressure Vessel Steel at Elevated Irradiation Temperature

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
E. A. Kuleshova ◽  
B. A. Gurovich ◽  
E. V. Krikun ◽  
A. S. Frolov ◽  
D. A. Maltsev ◽  
...  
Keyword(s):  
Pressure Vessel ◽  
Operating Temperature ◽  
Structural Phase ◽  
Irradiation Temperature ◽  
Reactor Pressure Vessel ◽  
Pressure Vessel Steel ◽  
Dislocation Loops ◽  
Radiation Induced ◽  
Higher Temperature ◽  
Reactor Pressure

This paper considers influence of elevated irradiation temperature on structure and properties of 15Kh2NMFAA reactor pressure vessel (RPV) steel. The steel is investigated after accelerated irradiation at 300°C (operating temperature of VVER-1000-type RPV) and 400°C supposed to be the operating temperature of advanced RPVs. Irradiation at 300°C leads to formation of radiation-induced precipitates and radiation defects-dislocation loops, while no carbide phase transformation is observed. Irradiation at a higher temperature (400°C) neither causes formation of radiation-induced precipitates nor provides formation of dislocation loops, but it does increase the number density of the main initial hardening phase—of the carbonitrides. Increase of phosphorus concentration in grain boundaries is more pronounced for irradiation at 400°C as compared to irradiation at 300°C due to influence of thermally enhanced diffusion at a higher temperature. The structural-phase changes determine the changes of mechanical properties: at both irradiation temperatures irradiation embrittlement is mainly due to the hardening mechanism with some contribution of the nonhardening one for irradiation at 400°C. Lack of formation of radiation-induced precipitates at T = 400°C provides a small ΔTK shift (17°C). The obtained results demonstrate that the investigated 15Kh2NMFAA steel may be a promising material for advanced reactors with an elevated operating temperature.

scholarly journals Modeling the Effect of Irradiation and Post-Irradiation Annealing on Grain Boundary Composition in Austenitic Fe-Cr-Ni Alloys

1998 ◽  
Vol 527 ◽  
Author(s):  
T.R. Allen ◽  
J.T. Busby ◽  
E. A. Kenik ◽  
G.S. Was
Keyword(s):  
Grain Boundary ◽  
Bulk Alloy ◽  
Model Calculations ◽  
Post Irradiation ◽  
Ni Alloys ◽  
Boundary Composition ◽  
Wide Range ◽  
Input Parameters ◽  
Radiation Induced ◽  
Single Set

ABSTRACTMany irradiation effects in Fe-Cr-Ni alloys such as radiation-induced segregation, radiation-enhanced diffusion, and void swelling are known to vary with bulk alloy composition. The development of microstructural and microchemical changes during irradiation and during post-irradiation annealing is determined by the rate of diffusion of point defects and alloying elements. To accurately predict the changes in grain boundary chemistry due to radiation-induced segregation and post-irradiation annealing, the composition dependence of diffusion parameters, such as the migration energy, must be known. A model has been developed which calculates migration energies using pair interaction energies, thereby accounting for the effect of composition on diffusivity. The advantages of this calculational method are that a single set of input parameters can be used for a wide range of bulk alloy compositions, and the effects of local order can easily be incorporated into the calculations. A description of the model is presented, and model calculations are compared to segregation measurements from seven different iron-chromium-nickel alloys, irradiated with protons to doses from 0.1 to 3.0 dpa at temperatures between 200°C and 600°C. Results show that segregation trends can be modeled using a single set of input parameters with the difference between model calculation and measurement being less than 5 at%, but usually less than 2 at%. Additionally, model predictions are compared to grain boundary composition measurements of neutron irradiated 304 stainless steel following annealing. For the limited annealing data available, model calculations correctly predict the magnitude and time scale for recovery of the grain boundary composition.

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