Research of the Effects on a Nuclear Cable Material Irradiated by Beta/Gamma Irradiation

2013 ◽  
Author(s):  
Weixia Zhong ◽  
Jiansheng Sun ◽  
Jinping Liu ◽  
Ping Sun
Keyword(s):  
Activation Energy ◽  
Glass Transition ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Irradiation Dose ◽  
Loss Modulus ◽  
Absorbed Dose ◽  
Transition Process ◽  
Gamma Irradiated ◽  
Movement Unit

In this paper, irradiated samples by different irradiation doses of the beta/gamma radiation from a selected nuclear cable material, which were studied by tensile machine, DSC and DMTA. The research results show that the elongation at break (EAB) drops with absorbed dose of beta/gamma radiation and at the same dose the EAB drop for beta-irradiated samples is higher than that for gamma-irradiated samples, which means that this material becomes more brittler with more irradiation. The OITP value for the irradiated samples exhibits pronounced drop with absorbed beta/gamma irradiation dose. And moreover, the OITP value of these gamma irradiated samples drops faster than that of those beta irradiated samples. DMTA researches show that the storage modulus (E′) and the loss factor (tanδ = E″/E′, E″ represents the loss modulus) of the irradiated samples present higher values with the increase dose of beta /gamma radiation. It is interest that the E′ behaves firstly an increase, then decreases by rising the temperature within the temperature range of −30–20 °C, and this trend becomes pronounced with increase of irradiation dose, combined with the activation energy, correspond to the glass transition process, for all the irradiated samples which hints that the glass transition process may be hindered in terms of a higher activation energy, but the movement unit could be smaller with a lower Tg, as a result of the beta/gamma irradiation.

scholarly journals The structure and glass transition behavior of PLLA under the influence of gamma radiation

2010 ◽  
Vol 64 (4) ◽  
pp. 275-281
Author(s):  
Dejan Milicevic ◽  
Sasa Trifunovic ◽  
Tihana Mudrinic ◽  
Andreja Leskovac ◽  
Nenad Ignjatovic ◽  
...  
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Gamma Radiation ◽  
Apparent Activation Energy ◽  
Absorbed Dose ◽  
Chain Scission ◽  
Transition Behaviour

The influence of gamma radiation on the structure and glass transition behavior of poly-L-lactide (PLLA) has been studied. Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by the gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC). The apparent activation energy, ?H*, for the glass transition was determined on the basis of the heating rate dependence of the glass transition temperature, Tg. Our findings support the fact that chain scission is the main reason for the decrease of Tg and ?H* with the absorbed dose. At low doses, despite large changes in molecular weight, only small alterations are observed in the glass transition temperature and apparent activation energy. Further increase in the absorbed dose introduces not only significant changes in the molecular weight but also in the glass transition temperature and the activation energy. Such glass transition behaviour is a manifestation of a well-known effect of molecular weight on Tg, postulated by the Fox-Flory equation. However, all the observed alterations are small and tolerable at absorbed doses required for sterilization (up to 25 kGy in most circumstances). Furthermore, this study reveals that the radiation-induced changes in the molecular weight and the glass transition temperature occur in a predictable and fairly accurate manner. Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of PLLA based implants.

The Influence of Gamma Radiation on the Glass Transition of Hydroxyapatite/Poly L-Lactide Composite

2007 ◽  
Vol 555 ◽  
pp. 497-502
Author(s):  
Dejan Miličević ◽  
S. Trifunović ◽  
N. Ignjatović ◽  
E. Suljovrujić
Keyword(s):  
Activation Energy ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Structural Relaxation ◽  
Absorbed Dose ◽  
Gel Permeation Chromatography ◽  
Chain Scission ◽  
Scanning Calorimetry ◽  
Dsc Measurements

Hydroxyapatite/poly L-lactide (HAp/PLLA) is a composite biomaterial which has been widely utilized for substitution and reparation of the hard bone tissue. It is well known that gamma irradiation has been successfully employed in the modification/sterilization of such porous composites and that it has advantages over other procedures. In this study, differential scanning calorimetry (DSC) measurements were made to investigate the influence of the radiation on glass transition behavior and structural relaxation, as well as to estimate the activation energy for this process. The apparent activation energy ΔH* for structural relaxation in the glass transition region was determined on the basis of the heating rate dependence of the glass transition temperature Tg. Furthermore, the results were correlated with those obtained by gel permeation chromatography (GPC). Our findings support the fact that the radiation-induced chain scission in the PLLA phase is the main reason for the decrease of the glass transition temperature and/or activation energy with the absorbed dose.

Assessment of ochratoxin A stability following gamma irradiation: experimental approaches for feed detoxification perspectives

2016 ◽  
Vol 9 (2) ◽  
pp. 289-298 ◽  
Author(s):  
A. Mehrez ◽  
I. Maatouk ◽  
R. Romero-González ◽  
A. Ben Amara ◽  
M. Kraiem ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Moisture Content ◽  
Gamma Irradiation ◽  
Ochratoxin A ◽  
High Performance ◽  
Irradiation Dose ◽  
Initial Moisture Content ◽  
Absorbed Dose ◽  
Model Systems ◽  
Food Model

The present study evaluated the effect of gamma irradiation on the stability of ochratoxin A (OTA) under various conditions. The effects of the physical state of OTA (solid vs aqueous), initial OTA concentration, irradiation dose and dose rate as well as the presence of model substances simulating food matrix compounds on OTA radiostability were investigated. First, pure OTA with and without food model compounds including α-D-glucose (monosaccharide), Methyl α-D-glucopyranoside (starch) and the amino acid derivatives N-α-acetyl-L-lysine methyl ester and N-α-acetyl-L-cysteine methyl ester (protein models) were irradiated with doses of 2, 4 and 8 kGy applied at 15.117 and 108.24 Gy/min. Secondly, artificially OTA-contaminated wheat with different moisture content (11, 14 and 16%) was irradiated with doses of 2, 4 and 8 kGy applied at 63.39 Gy/min. Residual OTA levels were analysed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry. Solid OTA (50 and 3,200 ng/ml)showed great irradiation stability, even with irradiation doses up to 8 kGy. Under dry conditions, the presence of food model components did not affect OTA radiostability. However, in an aqueous solution, complete reduction was achieved at the initial OTA concentration of 50 ng/ml and irradiation dose of 2 kGy. Applying gamma irradiation to cereal-based food model systems produced a significant OTA reduction (5,000 µg/kg) of 47.2% in moistened wheat kernels (16%) with an absorbed dose of 8 kGy but failed to reduce the OTA content of low moisture content wheat (11%). These model experiments offered a useful tool to assess the main key factors affecting gamma irradiation-induced OTA reduction. Gamma irradiation is promising since the irradiation doses applied could partially reduce OTA contamination. Nevertheless, its efficacy was largely affected by initial moisture content and could be dangerous if toxic by-products are produced or nutritive quality is lost and needs further study.

scholarly journals Sterility of gamma-irradiated pathogens: a new mathematical formula to calculate sterilizing doses

2020 ◽  
Vol 61 (6) ◽  
pp. 886-894
Author(s):  
Eve V Singleton ◽  
Shannon C David ◽  
Justin B Davies ◽  
Timothy R Hirst ◽  
James C Paton ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Influenza A ◽  
Irradiation Dose ◽  
Semliki Forest Virus ◽  
High Titre ◽  
Mathematical Methods ◽  
Simple Method ◽  
Sterility Testing ◽  
Gamma Irradiated ◽  
Multiple Hit

Abstract In recent years there has been increasing advocacy for highly immunogenic gamma-irradiated vaccines, several of which are currently in clinical or pre-clinical trials. Importantly, various methods of mathematical modelling and sterility testing are employed to ensure sterility. However, these methods are designed for materials with a low bioburden, such as food and pharmaceuticals. Consequently, current methods may not be reliable or applicable to estimate the irradiation dose required to sterilize microbiological preparations for vaccine purposes, where bioburden is deliberately high. In this study we investigated the applicability of current methods to calculate the sterilizing doses for different microbes. We generated inactivation curves that demonstrate single-hit and multiple-hit kinetics under different irradiation temperatures for high-titre preparations of pathogens with different genomic structures. Our data demonstrate that inactivation of viruses such as Influenza A virus, Zika virus, Semliki Forest virus and Newcastle Disease virus show single-hit kinetics following exposure to gamma-irradiation. In contrast, rotavirus inactivation shows multiple-hit kinetics and the sterilizing dose could not be calculated using current mathematical methods. Similarly, Streptococcus pneumoniae demonstrates multiple-hit kinetics. These variations in killing curves reveal an important gap in current mathematical formulae to determine sterility assurance levels. Here we propose a simple method to calculate the irradiation dose required for a single log10 reduction in bioburden (D10) value and sterilizing doses, incorporating both single- and multiple-hit kinetics, and taking into account the possible existence of a resistance shoulder for some pathogens following exposure to gamma-irradiation.

Influence of Gamma Irradiation to Magneto-Impedance Ratio in the Electrodeposited [NiFe/Cu]4 Multilayer

2020 ◽  
Vol 855 ◽  
pp. 202-207
Author(s):  
Ismail ◽  
Bangun Pribadi ◽  
Vina Oktaria ◽  
Artono Dwijo Sutomo ◽  
Utari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Magnetic Property ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Morphological Structure ◽  
Impedance Ratio ◽  
Gamma Irradiated ◽  
Scanning Electron

Influence of gamma irradiation to the magneto-impedance ratio of the electrodeposited [NiFe/Cu]4 multilayer on meander-shape PCB substrate has been studied. The magneto-impedance ratios were measured for both un-irradiated and irradiated by gamma radiation of Co-60 with a total dose of 40 Gy. The morphological structure were done by using scanning electron microscopy (SEM). The decrease in grain size of the samples after Gamma irradiated is observed. The magnetic property modifies as consequence of the change in the microstructure samples. Within result, the magneto-impedance ratio decreases around 34.9% for irradiated sample.

Some Properties of the Glass Transition in the Amorphous Sb-As-S-Se-I System

2007 ◽  
Vol 555 ◽  
pp. 165-170
Author(s):  
F. Skuban ◽  
S.R. Lukić ◽  
D.M. Petrović ◽  
Mirjana Šiljegović
Keyword(s):  
Activation Energy ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Specific Heat ◽  
Heating Rate ◽  
Glass Composition ◽  
Transition Process ◽  
Abrupt Increase ◽  
Pseudobinary System

Transformations of glasses from the multicomponent pseudobinary system (As2Se3)100−x(SbSI)x were analyzed from the aspect of determining the glass transition temperature Tg, activation energy of the process Et, and characteristic changes of the specific heat. The established dependence of Tg on glass composition and heating rate served as the basis for determining the activation energy of glass transition process Et. An abrupt increase in the specific heat cp at the glass transition temperature was analyzed with the aim of classifying the materials according to the criterion of the so-called 'fragility'. It was found that the investigated glasses, i.e. their melts, belong to the group of thermodynamically 'strong' melts.

Fourier transform infrared spectroscopic study of gamma irradiated SiO2 nanoparticles

2018 ◽  
Vol 32 (07) ◽  
pp. 1850074 ◽  
Author(s):  
Elchin Huseynov ◽  
Adil Garibov ◽  
Ravan Mehdiyeva ◽  
Efsane Huseynova
Keyword(s):  
Fourier Transform ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Fourier Transform Infrared ◽  
Sio2 Nanoparticles ◽  
Infrared Spectroscopic Study ◽  
Bending Vibration ◽  
Before And After ◽  
Stretching Vibration ◽  
Gamma Irradiated

In the present work, nano SiO2 particles are investigated before and after gamma irradiation (25, 50, 75, 100 and 200 kGy) using Fourier transform infrared (FTIR) spectroscopy method for the wavenumber between 400–4000 cm[Formula: see text]. It is found that as a result of spectroscopic analysis, five new peaks have appeared after gamma radiation. Two of new obtained peaks (which are located at 687 cm[Formula: see text] and 2357 cm[Formula: see text] of wavenumber) were formed as a result of gamma radiation interaction with Si–O bonds. Another three new peaks (peaks appropriate to 941, 2052 and 2357 cm[Formula: see text] values of wavenumber) appear as a result of interaction of water with nano SiO2 particles after gamma irradiation. It has been defined as asymmetrical bending vibration, symmetrical bending vibration, symmetrical stretching vibration and asymmetrical stretching vibration of Si–O bonds appropriate to peaks.

scholarly journals Influence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene

Nukleonika ◽  
2014 ◽  
Vol 59 (4) ◽  
pp. 123-128 ◽  
Author(s):  
Yang Gao ◽  
Weifang Zheng ◽  
Xiaoming Cao ◽  
Shaolei Chen
Keyword(s):  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Volume Fraction ◽  
Degradation Products ◽  
Absorbed Dose ◽  
Solvent System ◽  
Radiation Stability ◽  
Purex Process ◽  
Washing Process ◽  
Gamma Radiolysis

Abstract In light of the issue of radiolysis of the solvent system in PUREX process, alpha and gamma radiation stability of tributyl phosphate (TBP)/kerosene (OK) have been studied in this paper, in which 238Pu dissolved in the organic phase and 60Co are selected as alpha and gamma irradiation sources, respectively. The amount of the degradation products not easily removed after the washing process has been measured by the plutonium retention. The effects of the absorbed dose, the TBP volume fraction, the cumulative absorbed dose and the presence of UO2 2+ and Zr4+ on the radiolysis of the solvents have been investigated. The results have indicated that the Pu retention increases with the increase of the absorbed dose after alpha or gamma irradiation, and is larger for the solvent containing less TBP. There is competition between UO2 2+ and Pu4+ to complex with the degradation products, and Zr4+ accelerates the radiolysis of the system.

Gamma Irradiation Effect on Load-Deflection Curve of Semiconductor Package

2011 ◽  
Vol 399-401 ◽  
pp. 912-915 ◽  
Author(s):  
Azman Jalar ◽  
Wan Yusmawati Wan Yusoff ◽  
Norinsan Kamil Othman ◽  
Shahrum Abdullah ◽  
Irman Abdul Rahman
Keyword(s):  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Irradiation Dose ◽  
Maximum Load ◽  
Radiation Environment ◽  
Irradiation Effect ◽  
Deflection Curve ◽  
Significant Change ◽  
Load Deflection Curve ◽  
Different Doses

The effect of different doses of gamma radiation (0.5 Gy, 1.5 Gy, 5.0 Gy, 10.0 Gy and 50 kGy) on the maximum load and deflection of the Single Die Quad Flat No Lead (SDQFN) semiconductor package has been investigated. The three-point technique was carried out to obtain the maximum load and deflection of the package. The results of irradiated SDQFN show the decreasing in their maximum load and deflection with the increasing of gamma irradiation dose. The higher gamma irradiation dose produced the more significant change in the load-deflection behaviour of the irradiated SDQFN. The package becomes prone to failure when exposed to the radiation environment.

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