YBa2Cu3Oy Superconducting Ceramics Incorporated with Different Types of Oxide Materials as Promising Radiation Shielding Materials: Investigation of The Structure, Morphology, and Ionizing Radiations Shielding Performances.

New series of YBCO ceramics samples doping with different oxides such as SiO2, WO3, Al2O3, and TiO2 were fabricated to study the ionizing radiation shielding properties. The structure and morphology were explored by X-ray diffraction (XRD) and scanning electron microscope (SEM). The shielding properties were investigated experimentally and theoretically to check the validity of the results. The investigated radiation shielding properties include the proton, neutron, and gamma-ray. The XRD results show the orthorhombic structure for all ceramics without any additional peaks related to WO3, SiO2, TiO2, and Al2O3. At the same time, the SEM results appear to have a significant differentiation in the granular behavior of all ceramics surfaces. The incorporation of WO3 to YBCO enhanced the ceramic density, whereas the addition of different oxides reduced the density for ceramic samples. This variation in density changed the radiation shielding results. The sample containing WO3 (YBCO-W) gives us better results in radiation shielding properties for gamma and neutron; the sample having Al2O3 (YBCO-Al) is superior in shielding results for charged particles. Finally, the possibility to use YBCO with various oxides in different ionizing radiation shielding fields can be concluded.

Experimental shielding properties for a novel glassy system.

In the current study, we fabricated a series of boro-tellurite glass samples with a composition 10SrO-10Al2O3-10MoO3-(70-x)B2O3-xTeO2, where (x = 0, 17.5, 35, 52.5, and 70 mol%) via an ordinary melt-quench method. The glass structure was explored by X-ray diffraction (XRD), physical and structural properties. XRD results affirm the existence of two broad peaks, proving the amorphous state of the current glasses. The acquired results exhibit a linear relationship between the density, Poisson's ratio, and the addition of TeO2 amounts. The addition of TeO2 to the glass system shows a rise in glass stability and a reduction in packing density. Additionally, the values of mass attenuation coefficient (MAC) were determined experimentally within five energies (0.184, 0.280, 0.661, 0.710, and 0.810 MeV) from two radiation sources (166Ho and 137Cs). The (MAC)exp results were compared with XCOM values, and the compared values showed excellent compatibility. From the experimental results, many radiation shielding features involving half-value layer (HVL), mean free path (MFP), tenth value layer (TVL), and radiation protection efficiency (RPE) were computed. From the obtained results, it can be concluded that the TeSB4 sample has the highest stability and absorption for radiation, indicating the ability to use it as a radiation shielding substance.

Verification of the pure alanine in PMMA tube dosimeter applicability for dosimetry of radiotherapy photon beams: a feasibility study.

Alanine dosimeters in the form of pure alanine powder in PMMA plastic tubes were investigated for dosimetry in a clinical application. Electron paramagnetic resonance (EPR) spectroscopy was used to measure absorbed radiation doses by detection of signals from radicals generated in irradiated alanine. The measurements were performed for low-dose ranges typical for single-fraction doses often used in external photon beam radiotherapy. First, the dosimeters were irradiated in a solid water phantom to establish calibration curves in the dose range from 0.3 to 3 Gy for 6 and 18 MV X-ray beams from a clinical linear accelerator. Next, the dosimeters were placed at various locations in an anthropomorphic pelvic phantom to measure the dose delivery of a conventional four-field box technique treatment plan to the pelvis. Finally, the doses measured with alanine dosimeters were compared against the doses calculated with a commercial treatment planning system (TPS). The results showed that the alanine dosimeters have a highly sensitive dose response with good linearity and no energy dependence in the dose range and photon beams used in this work. Also, a fairly good agreement was found between the in-phantom dose measurements with alanine dosimeters and the TPS dose calculations. The mean value of the ratios of measured to calculated dose values was found to be near unity. The measured points in the in-field region passed dose-difference acceptance criterion of 3% and those in the penumbral region passed distance-to-agreement acceptance criterion of 3 mm. These findings suggest that the pure alanine powder in PMMA tube dosimeter is a suitable option for dosimetry of radiotherapy photon beams.

Exposure assessment of radon in the drinking water supplies: a descriptive study in Palestine.

BACKGROUND: Radon gas is considered as a main risk factor for lung cancer and found naturally in rock, soil, and water. The objective of this study was to determine the radon level in the drinking water sources in Nablus city in order to set up a sound policy on water management in Palestine. METHODS: This was a descriptive study carried out in two phases with a random sampling technique in the second phase. Primarily, samples were taken from 4 wells and 5 springs that supplied Nablus city residents. For each source, 3 samples were taken and each was analyzed in 4 cycles by RAD 7 device manufactured by Durridge Company. Secondly, from the seven regions of the Nablus city, three samples were taken from the residential tap water of each region. Regarding the old city, ten samples were taken. Finally, the mean radon concentration value for each source was calculated. RESULTS: The mean (range) concentration of radon in the main sources were 6.9 (1.5-23.4) Becquerel/liter (Bq/L). Separately, springs and wells' means were 4.6 Bq/L and 9.5 Bq/L; respectively. For the residential tap water in the 7 regions, the results of the mean (range) concentration values were found to be 1.0 (0.9-1.3) Bq/L. For the old city, the mean (range) concentration values were 2.3 (0.9-3.9) Bq/L. CONCLUSIONS: Except for Al-Badan well, radon concentrations in the wells and springs were below the United State Environmental Protection Agency maximum contaminated level (U.S EPA MCL). The level was much lower for tap water. Although the concentration of radon in the tap water of old city were below the MCL, it was higher than other regions in the city. Preventive measures and population awareness on radon's exposure are recommended.