The oxidation of ferrous to ferric ions due to ionizing radiation has been used for chemical dosimetry since 1927. The introduction of metal indicator dye xylenol orange (XO) sensitises the measurement of ferric ion yield. A ferrous sulphate- agarose- xylenol orange (FAX) gel was prepared and the gel then exposed to dose ranging from 0.2 to 10 Gy using various high energy photon and electron beams from a linear accelerator. Some general characteristics of FAX such as energy dependence, optical density (OD)-dose relationship, reproducibility and auto-oxidation of ferrous ions were analysed. The radiation yield G of the gel was calculated for gels prepared in oxygen and in air and the values were 46.3 +/- 2.1 and 40.9 +/- 1.4 Fe3+ per 100 eV for photons respectively. However for stock gel which was kept for 5 days pre-irradiation the G value decreased to 36.6 +/- 1.1. The gel shows linearity in OD-dose relationship, energy independence and reproducibility over the dose range investigated. Auto-oxidation of ferrous ions resulted in optical density changes of less than 1.5% per day.
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http://dx.doi.org/10.1007/BF03178418 | DOI Listing |
Int J Biol Macromol
June 2024
Cooperative Innovation Center of Industrial Fermentation, Ministry of Education & Hubei Province, Hubei University of Technology, Wuhan 430068, China; School of Life and Health Sciences, Hubei University of Technology, Wuhan 430068, China. Electronic address:
To obtain efficient natural food packaging materials, we utilized acorn starch (AS)-based film strengthened by feruloylated arabinoxylan (FAX) gel and additional retrogradation treatment to extend the shelf life of Agaricus bisporus (A. bisporus). Fourier transform infrared spectroscopy (FT-IR), confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM) analyses showed that due to the strong hydrogen bonding between FAX and starch molecules, physical crosslinking occurred between FAX and starch molecules in the composite film, and the microstructure became more compact.
View Article and Find Full Text PDFJ Med Phys
March 2022
Departement of Medical Physics, Nuclear Research Center of Algiers, Algiers, Algeria.
The effective atomic number and electron density of some Fricke gel dosimeters were calculated for photon interaction in the energy range from 10 keV to 1000 MeV using Auto-Z, direct and power law methods. The results are presented relative to those of water to allow direct comparison. It is found, that the effective atomic numbers and effective electron densities calculated with the Auto-Z and direct methods, demonstrates a good agreement in the energy interval extending from 0.
View Article and Find Full Text PDFRadiol Phys Technol
March 2021
Secondary Standard Dosimetry Laboratory, Nuclear Research Center of Algiers, 02 Boulevard Frantz Fanon, B.P.399, Algiers, Algeria.
Fricke gel dosimetry is a valuable technique used for recording 3D dose distribution in radiotherapy. Herein, we present the dosimetric characteristics of a synthesized ferrous-agarose-xylenol orange gel dosimeter in a clinical Co beam. Experimental data were obtained using a secondary standards dosimetry laboratory Co therapy unit.
View Article and Find Full Text PDFAustralas Phys Eng Sci Med
June 2007
School of Physics, Universiti Sains Malaysia, Penang, Malaysia.
The oxidation of ferrous to ferric ions due to ionizing radiation has been used for chemical dosimetry since 1927. The introduction of metal indicator dye xylenol orange (XO) sensitises the measurement of ferric ion yield. A ferrous sulphate- agarose- xylenol orange (FAX) gel was prepared and the gel then exposed to dose ranging from 0.
View Article and Find Full Text PDFMed Phys
September 2003
Centre for Medical, Health and Environmental Physics, Queensland University of Technology, Brisbane, Queensland 4101, Australia.
Glucose, sucrose, starch, and locust bean gum have been used as additives to the ferrous-agarose-xylenol orange (FAX) gel dosimeter. The saccharide enhanced dosimeters were found to have a higher dose sensitivity over a standard FAX gel as measured by both optical density change and magnetic resonance imaging (MRI). With optical density measurement, OD-dose sensitivity increases were up to 55% for glucose, 122% for sucrose and 43% for starch, while locust bean gum did not give a consistent response.
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