The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (H_ex, H_in), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Ra_eq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core ²³²Th/²³⁸U mass fractions were determined from the obtained values of ²³⁸U, ²³²Th and ⁴⁰K for the examined rocks of Seih-Sidri area. The average ²³⁸U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one’s radiological health.

The precursor nanoparticles of nickel hydroxide (Ni(OH)₂) and nickel oxide (NiO) were successfully converted into the latter by the reaction of nickel chloride with hydrazine at ambient temperature. (TGA) and (DSC) were adapted for annealing the precursor products at different annealing temperatures (210, 285, 350, 390, 425, and 450 °C). XRD, TEM, and UV-VIS absorption spectroscopy were used to characterize the products. Both the band edge and energy gap values decrease with increasing annealing temperatures. Hysteresis loops are visible in the M-H curves of annealed (350 °C and 390 °C) precursor NiO NPs, indicating the presence of ferromagnetic Ni domains. However, NiO nanoparticles annealed at higher temperatures (425 °C and 450 °C) had a straight M-H curve, indicating paramagnetic properties. NiO NPs were used to study photocatalysis in the degradation of the MB dye. As annealing temperatures increased, the catalyst caused the degradation of MB. The sample that was annealed at 450 °C, however, exhibits the maximum photocatalytic activity, reaching up to 72.4% after being exposed to visible light. In other words, it was discovered that as the catalyst’s annealing temperature rose, so did the rate of MB’s photocatalytic degradation.

In this paper, we present a study of the phototransference thermoluminescence (PTTL) of charges from deep traps in natural phosphate, using 254nm UV radiation. The natural material glow curve has one peak at 260°C, while the phototransfered glow curves has an additional peak at 150°C. The optimal conditions were illumination time of 180 min, and a preheating temperature of 500°C. The PTTL signal was found to be linear over the gamma (γ) dose range 0.1Gy-1000Gy. The efficiency of low dose reassessment reaches about 100 percent of the first readout. After two weeks of storage the PTTL signal was found to be 98 % of the original value. The results show the convenience of this method for the purpose of dose re-estimation over the dose range 0.1-5Gy. Such method is useful in radiation retrospective dosimetry and dating.

Radiation measurements related to nuclear accidents or terrorist events suffer from defects such as sample preparation time and variation in sample sensitivity. The objective of this study was to examine the potential use of a natural rock as a retrospective dosimeter. The research was carried out on the Saudi metamorphic rock slate originated from Asir. The technique used in this study was thermoluminescence (TL) dosimetry. Slate sample was exposed to gamma doses from100mGy to 1500Gy at King Saud University using a calibrated ⁶⁰Co source. For that, we investigate (i) effect of thermal treatment (ii) individual glow peak dose response (iii) batch homogeneity (iv) sensitivity and (v) effect of fading. Indications are that this material is possible candidate for dose reconstruction in retrospective dosimetry, and industrial applications under certain restricted conditions. Pre-sampling calibration in vitro may be necessary depending on the accuracy required in the dose estimate.