Yazar "Madkhali, O." seçeneğine göre listele

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    Radiation-induced thermoluminescence in Ca5(PO4)3OH powder from eggshell: Trapping parameter assessment
    (Pergamon-Elsevier Science Ltd, 2024) Souadi, G.; Bulcar, K.; Yucel, A.; Oglakci, M.; Sezer, S.; Madkhali, O.; Can, N.
    This study examines the thermoluminescence (TL) properties exhibited by hydroxyapatite (HAp) samples. The HAp samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. XRD results confirm that Hap corresponds to a hexagonal structure with a space group of P63/m. The study emphasizes the critical role of appropriate band-pass filters in TL measurements and explores the dose-dependent behavior of TL glow peaks. Examining the impact of varying heating rates (HR) on TL peak intensities revealed a positive correlation between HR and TL maximum peak temperatures, accompanied by a decrease in TL intensities. Notably, no thermal quenching effect was observed in HAp samples. The activation energy values were 0.51, 1.12, and 1.57 eV for Hoogenstraaten's method and 0.55, 1.19, and 1.65 eV for the Booth-BohunPorfianovitch method, demonstrating their consistency and robustness. Additionally, Tm-Tstop analysis was employed to identify distinct trap levels and calculate their respective activation energies. This study establishes a solid foundation for characterizing TL properties in HAp samples, shedding light on their potential applications in various fields. The findings provide valuable insights for the design and development of efficient catalysts for diverse applications.
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    Thermoluminescence of hydroxyapatite from eggshell powders doped with Dy synthesized by the sonication chemical method: Effects of doping concentration and heating rate
    (Elsevier, 2023) Bulcar, K.; Oglakci, M.; Yucel, A.; Sezer, S.; Madkhali, O.; Depci, T.; Can, N.
    Hydroxyapatite (HAP) was selected as the host material and synthesized using a sonication chemical method. The effect of Dy3+ ion doping concentrations (0.25, 0.5, 1, 2, 3, 4, 5, 7, and 10 wt%) on the structure and thermoluminescence was examined. The TL properties of Dy3+ doped HAP were also studied, including dose response, repeatability, and heating rate. Based on the glow curves of samples with a heating rate of 2 degrees C/s after beta irradiation to 20 Gy, three effective peak maxima appeared to make up the glow curves located at around 84, 190, and 318 degrees C. However, four levels of activation energy were observed by Tm-Tstop analysis. The kinetic analysis of four peaks obtained via computerized glow curve deconvolution revealed trap depths of 0.80, 0.95, 1.20, and 1.51 eV, with corresponding frequency factors of 1010, 1011, 1012, and 1011 s-1, respectively. Parallel investigations using the initial rise and variable heating rate approaches yielded comparable trap depth esti-mates. The dose dependence of the glow curves was determined to be linear across the 0.1-20 Gy range.