Hora Kavarian; Armin Mosayebi; Hamideh Daneshvar
Abstract
In this research work, commercial beta-tricalcium phosphate powder is converted into tablets by pressure-less sintering method. Thermoluminescence responses of tablet and powder samples in the dose range of 20 to 1500 Gy have been compared and effective factors in tablet conversion such as mass in the ...
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In this research work, commercial beta-tricalcium phosphate powder is converted into tablets by pressure-less sintering method. Thermoluminescence responses of tablet and powder samples in the dose range of 20 to 1500 Gy have been compared and effective factors in tablet conversion such as mass in the range of 30 to 60 mg, force between 1 to 3 N, concentration of granulating solution and tablet diameter in the range of 0.4 to 15 mm are investigated based on the results of dosimetric response and tablet hardness. The results show that by turning into tablets, the grain size increases, and the possibility of the first-order kinetics increases by the conversion of powders into tablets. It is possible to achieve a better dosimetric response than the it’s powder by applying suitable conditions for turning into tablets; also, the diameter of the sample can affect hardness, and it is better to make the tablets with a smaller size. Based on the results obtained from fading, reproducibility, sensitivity, peak shaping of the glow curve, and microhardness measurement, it can be seen that the samples that have been subjected to less pressure perform better and in order to achieve the desired results of converting to TLD dosimetry tablets, it is better to use more mass for tablets if more pressure is needed.
Parisa Taghipour; Farhad Zolfagharpour; Hamideh Daneshvar
Abstract
In this research work, powder hydroxyapatite samples were synthesized using a solid-state reaction method to investigate the annealing effect. The crystal structure was carried out by XRD system produced data, and the Rietveld method using MAUD software. The samples were irradiated in different radiation ...
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In this research work, powder hydroxyapatite samples were synthesized using a solid-state reaction method to investigate the annealing effect. The crystal structure was carried out by XRD system produced data, and the Rietveld method using MAUD software. The samples were irradiated in different radiation absorbed doses up to 1500Gy and their thermoluminescence properties including glow curve, response, fading effect and reproducibility were investigated from dosimetry point of view. The results showed that the annealing temperature significantly affects the crystal structure and thermoluminescence dosimetry response of hydroxyapatite samples, consequently. It was concluded that high temperature annealing process can lead to formation of β-TCP crystal phase during the synthesis of hydroxyapatite. Percentage of this formed phase increases with rising the temperature, and finally leads to increasing of the thermoluminescence response. It was concludded that in the solid state reaction method to increasing the TL response, it is better to use high annealing temperature for the synthesis of hydroxyapatite sample.
