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Showing 2 results for Al Hassan
M.m.m. Ali, Ph.d., H. Zhao, A. Rawashdeh, Y.a. Mohammed, M. Al Hassan,
Volume 19, Issue 3 (7-2021)
Abstract
Background: This study aimed to investigate the radiation hazard indices from sand samples of Ma’rib Governorate in Yemen, where the majority of oil and gas facilities are installed. Methods and Materials: Thirty five samples of desert sand from Ma’rib Governorate in Yemen were collected and tested their radiation hazard indices by using High Purity Germanium (HPGe) detector. Results: Based on the measurement of the concentrations of 226Ra, 232Th, and 40K, the radium equivalent activity (Raeq), the activity concentration index (Iγ), the external hazard index (Hex) and the internal hazard index (Hin) were all calculated. Also, the absorbed dose rate in Air (ADR) and the annual effective dose (AED) are calculated. Conclusions: Comparing the practically attained results with internationally permissible values, it was found that most of the radiological parameters, including the radiation hazard indices of the studied samples, fall within the world's permissible limits and don't expose risks to the human beings and environments.
Dr. M. Al Hassan, W.b. Liu, J. Wang, M.m.m. Ali, A. Rawashdeh,
Volume 20, Issue 3 (7-2022)
Abstract
Background: Recently, it has been demonstrated that thermosetting polymer composites have excellent gamma-rays shielding properties. Among them, phthalonitrile composites are the best suitable materials to replace the traditional shielding materials such as lead and concrete. Furthermore, tungsten-boride as high Z-material is an effective ionizing radiation shield. Materials and Methods: The gamma rays shielding properties of the phthalonitrile matrix (PH) reinforced with tungsten-boride (WB) at 661, 1172, and 1332 keV photon energies were investigated using MCNPX code and XCOM tool kit and compared to those of concrete as conventional shielding material and epoxy composites. MCNPX geometry was defined along the z-axis and described in the input file. The number of emitted photons was fixed at 107 at the source, which is supposed to be a monoenergetic point. Results: The simulated mass attenuation coefficients results are in good agreement with those calculated using the XCOM tool kit. Also, it was observed that at 661 keV photon energy, the shielding performances in term of Half-Value-Layer (HVL) are enhanced by3.08% and 22.01% for 30% and 50% of tungsten-boride concentrations compared to 30% of PbO concentration in the Epoxy-Clay composite and concrete respectively. Conclusion: In this study, the outstanding results of gamma-rays shielding properties of Phthalonitrile/WB composites (PHWB) obtained using MCNPX code and XCOM can be used for future experimental gamma-rays shielding approaches at a wide range of energy.
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