The international calibration procedure for B3 film dosimetry system to ensure the quality irradiated products by 10 MeV electron beam accelerators at VINAGAMMA

We performed an in-plant calibration of dosimetry system by electron beam (EB)irradiating the B3 film dosimeters at VINAGAMMA, and inter-compared with the alanine dosimetry, which were supplied and analyzed by Risø High Dose Reference Laboratory (HDRL) as the reference standard. The results revealed that the relative deviation between the values of absorbed doses obtained with our dosimeter and the transfer standards dosimeter measured by HDRL was within the acceptable limitation (about ± 3.0 % in the target range of 2.0-10.0 kGy). And post-irradiation stability of B3 film dosimeters was still maintained after 180 days storage. It is suggested that the B3 filmdosimetry could be used in routine radiation processing at VINAGAMMA with the investigated dose range for quality assurance of the irradiated products, specially are foods and foodstuffs processed under the 10 MeV EB accelerator at VINAGAMMA.

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Dosimetric evaluation of methyl red radiochromic film for radiation processing

Pigment & Resin Technology ◽

10.1108/prt-02-2020-0008 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Awad AL Zahrany ◽

Khalid Rabaeh ◽

Molham Eyadeh ◽

Ahmed Basfar

Keyword(s):

Gamma Ray ◽

Dose Range ◽

Absorbed Dose ◽

Radiochromic Film ◽

High Dose ◽

Methyl Red ◽

Radiation Processing ◽

Content Type ◽

The Stability ◽

The Impact

Purpose The purpose of this paper is to present a radiochromic film dosimeter containing polyvinyl alcohol (PVA) matrix and various concentrations of methyl red (MR) dye for high dose measurements. Design/methodology/approach The MR-PVA films were exposed to irradiation up to 60 kGy using 60Co source of gamma ray. The ultraviolet and visible regions (UV/VIS) spectrophotometry were used to examine the optical density of pre-and post-irradiated dosimeters at 424 nm. Findings The dose sensitivity of MR-PVA films increases significantly with increasing MR dye concentrations in the dose range of 5 to 60 kGy. The impact of relative humidity, irradiation temperature, dose rate and the stability of the films has been analyzed. The overall uncertainty of the MR-PVA film dosimeter is 6.12% (Double Standard-deviation, 95% confidence level). Practical implications It was found that the MR-PVA films may be used as high dose dosimeter with an acceptable overall uncertainty in routine industrial radiation processing. Originality/value The color bleaching of irradiated MR-PVA films in terms of specific absorbance curves increases significantly with increasing absorbed dose up to 60 kGy.

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Development of optical fibers for food irradiation dosimeter

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v15n2019.1009 ◽

2019 ◽

Vol 15 (1) ◽

pp. 109-111

Author(s):

Hamiza Ahmad Tajuddin ◽

Wan Muhamad Saridan Wan Hassan ◽

Siti Fairus Abdul Sani ◽

Siti Aiasah Hashim

Keyword(s):

Electron Beam ◽

Food Safety ◽

Optical Fibers ◽

Dose Range ◽

Radiation Detector ◽

Food Irradiation ◽

Consumer Confidence ◽

High Dose ◽

Linear Dose ◽

Irradiated Foods

Different technologies and methods for enhancing food quality have been developed and applied in the last few decades. One of the latest technologies is by using ionizing radiation. Food irradiation is the technology that improves the safety and extends the shelf life of food by reducing or eliminating harmful microorganisms and insects. In order to provide for food safety, proper control or radiation detector of irradiated food seems very critical to facilitate international trade of irradiated foods and to enhance consumer confidence. In present studies, germanium-doped (Ge-doped) optical fibers of various form and dimensions were used as radiation detector. The fibers were irradiated using electron beam (EPS 3000), with doses from 1 kGy up to 10 kGy, exceeding the dose range of all commercial high dose dosimeters used in food irradiation industry. A study has been made of linearity, reproducibility, and fading. The fibers show a linear dose response over the studied range doses with mean of reproducibility less than 5 % variation between 1st exposure and 2nd exposure. TL fading of Ge-doped flat fibers has been found to be < 8.7%.

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Calibration of routine dosimeters in radiation processing: Validation procedure for in-plant calibration

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp1103271s ◽

2011 ◽

Vol 26 (3) ◽

pp. 271-274

Author(s):

Bojana Secerov ◽

Goran Bacic

Keyword(s):

Calibration Procedure ◽

Standard Uncertainty ◽

Radiation Processing ◽

Calibration Laboratory ◽

Analysis Of Results ◽

Validation Procedure ◽

Dosimetry System ◽

Irradiation Geometry ◽

The Difference ◽

Specification Requirement

The essential prerequisite of radiation dosimetry is to provide quality assurance and documentation that the irradiation procedure has been carried out according to the specification requirement of correct calibration of the chosen dosimetry system. At the Radiation Plant of the Vinca Institute of Nuclear Sciences we compared two recommended protocols of irradiation procedures in the calibration of dosimetry systems in radiation processing: (1) by irradiation of routine dosimeters (ethanol-chlorobenzene - ECB) at the calibration laboratory and (2), by in-plant calibration with alanine transfer - dosimeters. The critical point for in-plant calibration is irradiation geometry, so we carefully positioned the phantom carrying both dosimeters in order to minimize dose gradients across the sample. The analysis of results obtained showed that the difference among determined absorbed doses for the construction of calibration curves between these two methods, (alanine vs. ECB), is less than 1%. The difference in combined standard uncertainty for each calibration procedure is 0.1%. These results demonstrate that our in-plant calibration is as good as calibration by irradiation at the calibration laboratory and validates our placement of the irradiation phantom during irradiation.

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Preparation of New ESR Dosimetry System for High Dose Radiation Processing

Egyptian Journal of Chemistry ◽

10.21608/ejchem.2020.21119.2259 ◽

2020 ◽

Vol 63 (4) ◽

pp. 9-10

Author(s):

essam faheem ◽

shadia moniem ◽

mohamoud el Ahdal

Keyword(s):

High Dose ◽

Radiation Processing ◽

Dosimetry System ◽

Dose Radiation

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Skin regeneration is accelerated by a lower dose of multipotent mesenchymal stromal/stem cells—a paradigm change

Stem Cell Research & Therapy ◽

10.1186/s13287-020-02131-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Gertraud Eylert ◽

Reinhard Dolp ◽

Alexandra Parousis ◽

Richard Cheng ◽

Christopher Auger ◽

...

Keyword(s):

Stem Cells ◽

Wound Healing ◽

Low Dose ◽

Dose Range ◽

High Dose ◽

Full Thickness ◽

Burn Wound ◽

Dermal Regeneration Template ◽

Yorkshire Pigs ◽

Stromal Stem Cells

Abstract Background Multipotent mesenchymal stromal/stem cell (MSC) therapy is under investigation in promising (pre-)clinical trials for wound healing, which is crucial for survival; however, the optimal cell dosage remains unknown. The aim was to investigate the efficacy of different low-to-high MSC dosages incorporated in a biodegradable collagen-based dermal regeneration template (DRT) Integra®. Methods We conducted a porcine study (N = 8 Yorkshire pigs) and seeded between 200 and 2,000,000 cells/cm2 of umbilical cord mesenchymal stromal/stem cells on the DRT and grafted it onto full-thickness burn excised wounds. On day 28, comparisons were made between the different low-to-high cell dose groups, the acellular control, a burn wound, and healthy skin. Result We found that the low dose range between 200 and 40,000 cells/cm2 regenerates the full-thickness burn excised wounds most efficaciously, followed by the middle dose range of 200,000–400,000 cells/cm2 and a high dose of 2,000,000 cells/cm2. The low dose of 40,000 cells/cm2 accelerated reepithelialization, reduced scarring, regenerated epidermal thickness superiorly, enhanced neovascularization, reduced fibrosis, and reduced type 1 and type 2 macrophages compared to other cell dosages and the acellular control. Conclusion This regenerative cell therapy study using MSCs shows efficacy toward a low dose, which changes the paradigm that more cells lead to better wound healing outcome.

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