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Theoretical calculations based on the Density Functional Theory (DFT) have been performed to investigate the interaction of H2S as well SO2 gaseous molecules at the surfaces of Be12O12 and Mg12O12 nano-cages. The results show that a Mg12O12 nano-cage is a better sorbent than a Be12O12 nano-cage for the considered gases. Moreover, the ability of SO2 gas to be adsorbed is higher than that of H2S gas. The HOMO–LUMO gap (Eg) of Be12O12 nano-cage is more sensitive to SO2 than H2S adsorption, while the Eg value of Mg12O12 nano-cage reveals higher sensitivity to H2S than SO2 adsorption. The molecular dynamic calculations show that the H2S molecule cannot be retained at the surface of a Be12O12 nano-cage within 300–700 K and cannot be retained on a Mg12O12 nano-cage at 700 K, while the SO2 molecule can be retained at the surfaces of Be12O12 and Mg12O12 nano-cages up to 700 K. Moreover, the thermodynamic calculations indicate that the reactions between H2S as well SO2 with Be12O12 and Mg12O12 nano-cages are exothermic. Our results suggest that we can use Be12O12 and Mg12O12 nano-cages as sorbents as well as sensors for H2S and SO2 gases. [ABSTRACT FROM AUTHOR]

The accumulations of beach placers along the shoreline of Hadhramout at As-Sufal area have been prospected and analyzed for their radiogenic and chemical characteristics for the first time. The activity concentrations of 226Ra, 232Th, and 40K in the beach placers' samples were measured by gamma-ray spectrometry using a 56% HPGe detector and found to be 1270±237, 2098±380, and 208±40Bqkg-1, respectively. The results established As-Sufal as a high natural background radiation area. The hazard indices predicted elevation of the external exposure of residents when sand soiled with beach placers from this area is used as a building material. Radium equivalents of beach placers were 8.6-14.3 times the maximum recommended for the safe use of materials in the construction of dwellings. The outdoor annual effective doses ranged from 1.68 up to ∼ 2.82 mSv considerably higher than the recommended 1-mSv dose limit for members of the general public. The beach placers at the study locations are dominated by TiO2, Fe2O3, and SiO2. Ir and Hf were found to be incorporated in Zr and Al compounds, respectively, and the anti-correlation of Zr with either Al or Hf indicates that Zr replaces both elements in the beach placers' grains. The radionuclides in beach placers seem to be attributed to Mg-, Ca-, Si-, and Zr-bearing minerals and not associated with Fe-bearing minerals. The heaviest fractions are mainly composed of TiO2, Fe2O3, and ZrO2. The TiO2-bearing minerals in the heaviest fractions contain V-rich portions. [ABSTRACT FROM AUTHOR]

This paper thoroughly examines lanthanum-doped lead titanate (PbLaxTi(1−0.75x)O3), a perovskite-based ceramic material, focusing on its structural properties, vibrational behavior, and radiation shielding capabilities. Using advanced techniques like X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM), we explore the intricate relationship between lanthanum doping levels and material properties. Additionally, we assess its radiation shielding potential through metrics. Computational approaches employing the FLUKA code help evaluate theoretical values. Our findings reveal that increasing lanthanum concentration alters crystal atom arrangement, influences vibrational patterns, and enhances radiation shielding effectiveness. Increasing lanthanum concentration resulted in a maximum 7.55% rise in the mass attenuation coefficient (MAC) at 0.059 MeV. The half-value layer (HVL) decreased by 4.68% at 1.33 MeV, and the mean free path (MFP) decreased by 5.78% at 1.41 MeV with increased lanthanum ratio. Moreover, the radiation protection efficiency (RPE) increased from 30.7779 to 32.67442% at 0.059 MeV as lanthanum content increased. These findings offer valuable insights into material characteristics and suggest potential applications in enhancing radiation shielding for medical and industrial purposes. This comprehensive analysis provides practical insights for potential applications, particularly in medical or industrial radiation protection. The data-driven approach here paves the way for future research at the intersection of data science and material science, advancing material design and understanding doped perovskite materials. [ABSTRACT FROM AUTHOR]

Occult hepatitis B virus (HBV) in blood donors is considered as a potential risk for transmission of HBV infection. The aim of this study was to determine the prevalence of anti-hepatitis B core antibody (anti-HBC) positivity in Egyptian blood donations as well as to estimate the frequency of HBV-DNA in anti-HBc-positive donations. The study included 760 Egyptian healthy blood donors, representing 26 different Egyptian governorates screened according to routine practice for the presence of hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibodies (Abs), HIV-1/2 Abs and Treponema Abs. The accepted blood units for donation were tested for the presence of total anti-HBc Abs by two tests. Positive units for anti-HBc were further tested for HBV-DNA by polymerase chain reaction. According to routine screening, a total of 48/760 units (6·3%) were rejected [38 (5%) HCV-Ab-positive units, 9 (1·18%) HbsAg-positive units and 1 (0·13%) Treponema-Ab-positive unit]. Among the accepted blood units for donation, prevalence of anti-HBc was 78/712 units (10·96%). HBV-DNA was detected in 9/78 (11·54%) of the anti-HBc-positive units, and thus, occult HBV infection was detected in 9/712 (1·26%) of the accepted blood donations. Implementing anti-HBc test to the routine assay for the forthcoming two decades would certainly eliminate possible HBV-infected units. Rejection of these units will be beneficial to decrease the risk of HBV transmission with its potential consequences particularly in immunocompromised recipients. [ABSTRACT FROM AUTHOR]