scholarly journals Polymer Film Blend of Polyvinyl Alcohol, Trichloroethylene and Cresol Red for Gamma Radiation Dosimetry

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1866
Author(s):  
Aris Doyan ◽  
Susilawati Susilawati ◽  
Saiful Prayogi ◽  
Muhammad Roil Bilad ◽  
Muhamad Fatikul Arif ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Polyvinyl Alcohol ◽  
Polymer Film ◽  
Potential Application ◽  
Radiation Dosimetry ◽  
Energy Gap ◽  
Dose Range ◽  
Color Changes ◽  
Γ Rays ◽  
Cresol Red

This study investigated the polymer film composite of polyvinyl alcohol (PVA), trichlorethylene (TCE) and cresol red (CR) dye irradiated with gamma (γ) rays for potential application as radiation dosimetry. The film was prepared via the solvent-casting method with varying concentrations of TCE. Film samples were exposed to radiation from a γ-rays radiation source of 60Cobalt isotope. Color changes before and after γ-rays irradiation were observed, and the optical properties of the polymer films were investigated by spectrophotometry. Results show that increasing the radiation dose physically changed the color of the polymer film, from purple (pH > 8.8) without radiation (0 kGy) to yellow (almost transparent) (2.8 < pH < 7.2) at the highest dose (12 kGy). The concentration of acid formed due to irradiation increased with the increase in irradiation doses and at higher TCE content. The critical doses of PVA-TCE composites decreased linearly with the increase of TCE composition, facilitating an easy calibration process. The dose response at 438 nm increased exponentially with increasing radiation dose, but showed an opposite trend at the 575 nm band. An increase in the TCA concentration indicated a decrease in the absorption edge and an increase in activation energy, but both decreased for all TCE concentrations at higher doses. The energy gap for the direct and the indirect transitions decreased with increasing TCE concentration and γ-rays radiation dose. The results of this study demonstrated the potential application of PVA-TCE-CR polymer film as γ-rays irradiation dosimetry in a useful dose range of 0–12 kGy.

scholarly journals Optical Properties and Conductivity of PVA–H3PO4 (Polyvinyl Alcohol–Phosphoric Acid) Film Blend Irradiated by γ-Rays

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1065
Author(s):  
Susilawati Susilawati ◽  
Saiful Prayogi ◽  
Muhamad F. Arif ◽  
Noor Maizura Ismail ◽  
Muhammad Roil Bilad ◽  
...  
Keyword(s):  
Optical Properties ◽  
Radiation Dose ◽  
Optical Absorption ◽  
Phosphoric Acid ◽  
Polyvinyl Alcohol ◽  
Polymer Film ◽  
Energy Gap ◽  
Visible Region ◽  
Ultraviolet Region ◽  
Γ Rays

This study assesses the optical properties and conductivity of PVA–H3PO4 (polyvinyl alcohol–phosphoric acid) polymer film blend irradiated by gamma (γ) rays. The PVA–H3PO4 polymer film blend was prepared by the solvent-casting method at H3PO4 concentrations of 75 v% and 85 v%, and then irradiated up to 25 kGy using γ-rays from the Cobalt-60 isotope source. The optical absorption spectrum was measured using an ultraviolet–visible spectrophotometer over a wavelength range of 200 to 700 nm. It was found that the absorption peaks are in three regions, namely two peaks in the ultraviolet region (310 and 350 nm) and one peak in the visible region (550 nm). The presence of an absorption peak after being exposed to hυ energy indicates a transition of electrons from HOMO to LUMO within the polymer chain. The study of optical absorption shows that the energy band gap (energy gap) depends on the radiation dose and the concentration of H3PO4 in the polymer film blend. The optical absorption, absorption edge, and energy gap decrease with increasing H3PO4 concentration and radiation dose. The interaction between PVA and H3PO4 blend led to an increase in the conductivity of the resulting polymer blend film.

Study of Afterglow and Thermoluminescence Properties of Synthetic Opal-C Nanoparticles for In Vivo Dosimetry Applications

2013 ◽  
Vol 1530 ◽  
Author(s):  
Marlen Hernández-Ortiz ◽  
Laura S. Acosta-Torres ◽  
Rodolfo Bernal ◽  
Catalina Cruz-Vázquez ◽  
Víctor M. Castaño
Keyword(s):  
Radiation Dosimetry ◽  
Dose Range ◽  
Beta Particle ◽  
In Vivo Dosimetry ◽  
Synthetic Opal ◽  
Genotoxic Effects ◽  
Stöber Method ◽  
Particle Irradiation ◽  
The Stöber Method

ABSTRACTOpal particles, with diameter ca. 80 nm, were synthesized by the Stöber method. Samples were exposed to 100 Gy of beta particle irradiation and its thermoluminescence (TL) emission was recorded. TL response presents good reproducibility, standard deviation 1 %. The glow curve displays two TL peaks 86 and 400 °C and the afterglow (AG) phenomenon is observed immediately after irradiation (< 150°C). The synthetic opal-C exhibits a linear dependence of AG response as function of dose from 0.25 to 8 Gy. This dose range is of interest for personal and clinical dosimetry. Moreover, a previous study indicates that cytotoxic and genotoxic effects caused by opal nanoparticles, did not induce unrepairable DNA damage neither a cellular harm. Therefore, our results show synthetic opal-C is a material useful for in vivo radiation dosimetry.

scholarly journals Preliminary magnetic resonance relaxometric analysis of Fricke gel dosimeters produced with polyvinyl alcohol and glutaraldehyde

2017 ◽  
Vol 32 (3) ◽  
pp. 242-249 ◽  
Author(s):  
Salvatore Gallo ◽  
Giorgio Collura ◽  
Giuseppina Iacoviello ◽  
Anna Longo ◽  
Luigi Tranchina ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Polyvinyl Alcohol ◽  
Dose Range ◽  
Relaxation Times ◽  
Ion Concentration ◽  
Nuclear Magnetic Resonance Relaxometry ◽  
New Formulation ◽  
Nuclear Magnetic

This work describes the preliminary analysis of Fricke gels dosimeters characterized by a new formulation making use of a matrix of polyvinyl alcohol cross-linked by adding glutaraldehyde and analyzed by means of nuclear magnetic resonance relaxometry. In previous optical studies, these gels have shown promising dosimetric features in terms of photon sensitivity and low diffusion of ferric ions produced after irradiation. In this work, we used a portable nuclear magnetic resonance relaxometer to measure the relaxation times (which are important for dosimetric applications) of these gel materials. For this purpose, we performed a study for optimizing the acquisition parameters with a nuclear magnetic resonance relaxometer. Gel samples were exposed to clinical 6 MV photons in the dose range between 0 and 20 Gy. Nuclear magnetic resonance relaxometry measurements were per- formed and the sensitivity to photon beams was measured for various values of the Fe2+ ion concentration. The analyses pointed out that the MR signal increases as the Fe2+ content in- creases and the increase is about 75 % when the concentration of Fe2+ ions is increased from 0.5 mM to 2.5 mM. Furthermore, the sensitivity improvement achieved with increasing the Fe2+ concentration is about 60 %. This paper shows that the portable nuclear magnetic resonance relaxometer used for analysis of porous materials can be used for characterization of these dosimetric gels and this study can be considered as the first step for the characterization of these dosimeters which in future could be used for 3-D dose mapping in clinical applications.

Background Levels and Radiation Dose Yield of o-Tyrosine in Chicken Meat

1991 ◽  
Vol 54 (12) ◽  
pp. 935-938 ◽  
Author(s):  
NOEMI CHUAQUI-OFFERMANNS ◽  
TOM MCDOUGALL
Keyword(s):  
Radiation Dose ◽  
Dose Response ◽  
Response Curve ◽  
Dose Range ◽  
Background Level ◽  
Chicken Meat ◽  
Dose Response Curve ◽  
Poultry Meat ◽  
Wet Weight ◽  
The Mean

The measurement of o-tyrosine levels in poultry meat is a potential method for postirradiation dosimetry of poultry. The validity of using o-tyrosine for this purpose has not yet been established. As part of the validation process, the o-tyrosine content in unirradiated chicken meat, the radiation dose response curve, and the effects of postirradiation storage on o-tyrosine levels are examined. In 18 individual samples, the mean background level of o-tyrosine was 0.18 ± 0.11 ppm (wet weight, 70% moisture), and the most frequent background level (60% of the cases) was between 0.05 and 0.15 ppm (wet weight, 70% moisture). In pooled samples of 10 chickens, the mean background level was 0.12 ± 0.03 ppm (wet weight, 70% moisture). The levels were not significantly affected by storage at 5°C (7 d) or by freezing the sample. The radiation dose response curve was linear within the dose range studied (0 to 10 kGy), with a slope of 0.127 ± 0.003 ppm (wet weight)/kGy. Although there was some variation in the intercept (0.132 ± 0.013), the slope was the same in all samples tested. Postirradiation storage at either 4 or 8°C until spoilage did not affect the levels of o-tyrosine. These data indicate that o-tyrosine level may be useful for determining the absorbed dose in chicken meat gamma-irradiated to doses greater than 0.6 kGy. Further validation studies are continuing.

Effects of Surface Disordering on Optical & Mechanical Properties of Ar+ Implanted Polycarbonate

2012 ◽  
Vol 585 ◽  
pp. 537-541 ◽  
Author(s):  
Nidhi Shekhawat ◽  
Sanjeev Aggarwal ◽  
Annu Sharma ◽  
Krishan Gopal Murli Nair
Keyword(s):  
Structural Changes ◽  
Urbach Energy ◽  
Energy Gap ◽  
Dose Range ◽  
Spectroscopic Technique ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Energy Disorder ◽  
Uv Visible ◽  
Disorder Parameter

The surface disordering produced in polycarbonate specimens by 130 keV Ar+ ions has been investigated. The effect of argon ions on the surface structure of polycarbonate specimens has also been studied. The polycarbonate specimens were implanted with 130 keV Ar+ ions in the dose range of 1×1014-1×1016 ions cm-2. The change in the Urbach energy (disorder parameter) after implantation has been estimated using Urbach edge method by applying UV-Visible spectroscopic technique. Optical energy gaps of virgin as well as implanted specimens have also been calculated using UV-Visible spectroscopic technique. A clear enhancement in Urbach energy (disorder parameter) from 0.61 eV (virgin sample) to 1.38 eV (at a fluence of 1×1016 Ar+ cm-2) and a drastic decline in optical energy gap (4.1 eV to 0.63 eV) with increasing implantation dose has been observed. This decrease in optical energy gap has been found to have linear dependence on the increase in the Urbach energy which point towards the formation of disordered structures in the implanted layers of polycarbonate. The structural changes produced due to implantation have been studied using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopic technique. Furthermore, Knoop microhardness has been found to be enhanced 14 times (at a load of 9.8 mN) after implantation. The possible correlation of the increase in Knoop surface hardness with the structural changes observed as a result of implantation has been established and discussed.

Variables in the radiation-attenuation of helminth larvae: the effect of differences in quality of radiation

Parasitology ◽  
1966 ◽  
Vol 56 (4) ◽  
pp. 651-656 ◽  
Author(s):  
T. Kassai ◽  
B. Fitzpatrick ◽  
W. Mulligan
Keyword(s):  
Agricultural Research ◽  
Dose Range ◽  
X Rays ◽  
British Council ◽  
Agricultural Research Council ◽  
Radiation Sources ◽  
Γ Rays ◽  
Low Radiation Doses ◽  
Total Worm Burden

A comparison has been made of the attenuating effect on N. brasiliensis larvae of X-rays (HVL, 8 mm Al) and γ-rays from 60Co over the range 10–80 kr. In the dose range where attenuation was manifested as a decrease in total worm burden the γ-rays had an RBE (relative biological effect) of 0-7 relative to the X-rays as unity.Because of the enhancement of infectivity occurring at low radiation doses, attenuation in this region is better assessed in terms of alteration to the sex-ratio of the parasite rather than effect on total population.This work was supported by grants from the Agricultural Research Council and the Horse Race Betting Levy Board, and was carried out during the tenure by one of the authors (T. Kassai) of a British Council exchange scholarship.Thanks are due to Dr T. Martin Young and Mr J. S. Orr of the Radiotherapy Department, Western Infirmary, Glasgow, for access to radiation sources and helpful advice.

CVD Diamond Applications as TL Radiation Dosimeters

2007 ◽  
Vol 1039 ◽  
Author(s):  
M. Pedroza-Montero ◽  
R Melendrez ◽  
V Chernov ◽  
M. Pedroza-Montero ◽  
S Gastelum ◽  
...  
Keyword(s):  
Radiation Dosimetry ◽  
Dose Range ◽  
Research Work ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Synthetic Material ◽  
Ionization Chambers ◽  
Solubility In Water ◽  
Dose Rates ◽  
Linear Dose

AbstractThe extraordinary characteristics of chemically vapor deposited (CVD) diamond such as tissue equivalence, radiation hardness, and lack of solubility in water; makes CVD diamond a very promising material for radiation dosimetry applications. Recent investigations have shown that CVD techniques allowed the growing of good quality diamond films in a diversity of substrates to be used in the form of ionization chambers, thermoluminescence (TL) detectors and dosimeters. In the present work, we report on the TL properties of MWCVD diamond exposed to gamma radiation in the 0.05 -1.0 kGy dose range and 43.5 and 81.11 Gy min−1 dose rates. The CVD diamond displays a linear dose behavior and 5% TL cycle reproducibility, without requiring any annealing or thermal treatment before using it as TL dosimeter. In spite of the significant results, some problems remain and a lot of research work is necessary to improve the synthetic material characteristics to optimize the TL/OSL radiation dosimeter properties.

scholarly journals Molecular properties of polyvinyl alcohol/ sodium alginate composite

2019 ◽  
Vol 10 (1) ◽  
pp. 4734-4739
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
Density Functional ◽  
Energy Gap ◽  
Heat Of Formation ◽  
Thermal Parameters ◽  
Basis Set ◽  
Lumo Energy ◽  
Model Structures ◽  
Homo Lumo

Molecular and bimolecular properties are important factors to judge the functionality of polymer/biopolymer composites. Accordingly, molecular modeling is conducted to study the electronic properties of Polyvinyl Alcohol (PVA); Sodium Alginate (SA) as well as their composites. Accordingly, Density functional theory (DFT) at B3LYB level using 6-311/G (d, p) basis set is utilized to study the model structures. Total dipole moment (TDM), HOMO/LUMO energy gap, electrostatic potential (ESP) are calculated at B3LYB level for all studied structures. The results of TDM, HOMO/LUMO energy gap and ESP indicated that the TDM increased, HOMO/LUMO energy gap decreased and electro-negativity increased for the structures under study. Thermal parameters at PM6 are calculated including final heat of formation; free energy; entropy; enthalpy and heat capacity as a function of temperature. Thermal parameters show a variation with changing the site of interaction which indicated that the coordination of PVA/SA is an important factor for describing PVA/SA composite.

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