Newly Developed Vanadium-Based Glasses and Their Potential for Nuclear Radiation Shielding Aims: A Monte Carlo Study on Gamma Ray Attenuation Parameters

This study aimed to investigate different types of glasses based on the 46V₂O₅-46P₂O₅-(8-x) B₂O₃-xCuO system in terms of their nuclear radiation shielding properties. Accordingly, five different CuO-doped vanadate glasses were investigated extensively to determine the necessary gamma shielding parameters along with effective conductivity at 300,000 and buildup factors. Phy-x PSD software was used for determination of these vital parameters. Furthermore, these parameters, such as half value layer, tenth value layer, and mean free path were investigated in a broad energy range between 0.015 and 15 MeV. The results revealed that the amount of CuO reinforced in each sample plays an essential role in determination of the shielding abilities of the samples. The sample with the highest CuO content had the highest linear attenuation coefficient and mass attenuation coefficient values. Additionally, the lowest mean free path, half value layer, and tenth value layer values were recorded for glass sample VPCu8. There was an inverse relation between the effective conductivity and effective atomic number and photon energy; that is, as energy increases, the effective conductivity and effective atomic number decreased rapidly, especially in the regions of low energy. Glass sample VPCu8 reported the highest values for both parameters. Moreover, glass sample VPCu8 had the lowest exposure buildup factor and energy absorption buildup factor values. Our findings showed that CuO-reinforced vanadate glass composition, namely 46V₂O₅-46P₂O₅-8CuO, with a glass density of 2.9235 g/cm³, was reported to have superior gamma ray attenuation properties. These results would be helpful for scientists in determining the most appropriate additive rare earth type, as well as the most appropriate glass composition, to offer shielding characteristics similar to those described above, taking into consideration the criteria for usage and the needs of the community. The results of this research will be useful to the scientific community in evaluating the prospective characteristics of CuO-doped glass systems and related glass compositions. CuO-doped glass systems and associated glass compositions have a wide range of properties.     

The Influence of Titanium Dioxide on Silicate-Based Glasses: An Evaluation of the Mechanical and Radiation Shielding Properties

The mechanical and radiation shielding features were reported for a quaternary Na₂O-CaO-SiO₂-TiO₂ glass system used in radiation protection. The fundamentals of the Makishima–Mazinize model were applied to evaluate the elastic moduli of the glass samples. The elastic moduli, dissociation energy, and packing density increased as TiO₂ increased. The glasses’ dissociation energy increased from 62.82 to 65.33 kJ/cm³, while the packing factor slightly increased between 12.97 and 13.00 as the TiO₂ content increased. The MCNP-5 code was used to evaluate the gamma-ray shielding properties. The best linear attenuation coefficient was achieved for glass samples with a TiO₂ content of 9 mol%: the coefficient decreased from 5.20 to 0.14 cm⁻¹ as the photon energy increased from 0.015 to 15 MeV.     

Spectroscopic Properties of Inorganic Glasses Doped with Pr3+: A Comparative Study

The results presented in this communication concern visible and near-IR emission of Pr³⁺ ions in selected inorganic glasses, i.e., borate-based glass with Ga₂O₃ and BaO, lead-phosphate glass with Ga₂O₃, gallo-germanate glass modified by BaO/BaF₂, and multicomponent fluoride glass based on InF₃. Glasses present several emission bands at blue, reddish orange, and near-infrared spectral ranges, which correspond to 4f–4f electronic transitions of Pr³⁺. The profiles of emission bands and their relative intensity ratios depend strongly on glass-host. Visible emission of Pr³⁺ ions is tuned from red/orange for borate-based glass to nearly white light for multicomponent fluoride glass based on InF₃. The positions and spectral linewidths for near-infrared luminescence bands at the optical telecommunication window corresponding to the ¹G₄ → ³H₅, ¹D₂ → ¹G₄, and ³H₄ → ³F₃,³F₄ transitions of Pr³⁺ are dependent on glass-host matrices and excitation wavelengths. Low-phonon fluoride glasses based on InF₃ and gallo-germanate glasses with BaO/BaF₂ are excellent candidates for broadband near-infrared optical amplifiers. Spectroscopic properties of Pr³⁺-doped glasses are compared and discussed in relation to potential optical applications.     

A Closer Look on Nuclear Radiation Shielding Properties of Eu3+ Doped Heavy Metal Oxide Glasses: Impact of Al2O3/PbO Substitution

In this study, a group of heavy metal oxide glasses with a nominal composition of 55B₂O₃ + 19.5TeO₂ + 10K₂O + (15−x) PbO + xAl₂O₃ + 0.5Eu₂O₃ (where x = 0, 2.5, 5, 7.5, 10, 12.5, and 15 in wt.%) were investigated in terms of their nuclear radiation shielding properties. These glasses containing lanthanide-doped heavy metal oxide were envisioned to yield valuable results in respect to radiation shielding, and thus a detailed investigation was carried out; the obtained results were compared with traditional and new generation shields. Advanced simulation and theoretical methods have been utilized in a wide range of energy regions. Our results showed that the AL0.0 sample with the highest PbO contribution had superior shielding properties in the entire energy range. The effective removal of cross-sections for fast neutrons (Σ_R) was also examined. The results indicated that AL5.0 had the greatest value. While increasing the concentration of Al₂O₃ in samples had a negative effect on the radiation shielding characteristics, it can be concluded that using PbO in the Eu³⁺ doped heavy metal oxide glasses could be a useful tool to keep gamma-ray shielding properties at a maximum level.     

Trivalent Ions and Their Impacts on Effective Conductivity at 300 K and Radio-Protective Behaviors of Bismo-Borate Glasses: A Comparative Investigation for Al,Y, Nd,Sm, Eu

We aimed to determine the contribution of various trivalent ions like Al and rare-earths (Y, Nd, Sm, Eu) on resistance behaviors of different types of bismo-borate glasses. Accordingly, eight different bismuth borate glasses from the system: 40Bi₂O₃–59B₂O₃–1Tv₂O₃ (where Tv = Al, Y, Nd, Sm, and Eu) and three glasses of (40Bi₂O₃–60B₂O₃; 37.5Bi₂O₃–62.5B₂O₃; and 38Bi₂O₃–60B₂O₃–2Al₂O₃) compositions were extensively investigated in terms of their nuclear attenuation shielding properties, along with effective conductivity and buildup factors. The Py-MLBUF online platform was also utilized for determination of some essential parameters. Next, attenuation coefficients, along with half and tenth value layers, have been determined in the 0.015 MeV–15 MeV photon energy range. Moreover, effective atomic numbers and effective atomic weight, along with exposure and energy absorption buildup factors, were determined in the same energy range. The result showed that the type of trivalent ion has a direct effect on behaviors of bismo-borate glasses against ionizing gamma-rays. As incident photon energy increases, the effective thermal conductivity decreases rapidly, especially in the low energy range, where photoelectric effects dominate the photon–matter interaction. Sample 8 had the minimum heat conductivity at low photon energies; our findings showed that Eu-reinforced bismo-borate glass composition, namely 40Bi₂O₃–59B₂O₃–1Eu₂O₃, with a glass density of 6.328 g/cm³ had superior gamma-ray attenuation properties. These outcomes would be useful for the scientific community to observe the most suitable additive rareearth type and related glass composition for providing the aforementioned shielding properties, in terms of needs and utilization requirements.     

Shielding Properties of Some Marble Types: A Comprehensive Study of Experimental and XCOM Results

In this work, some marble types were collected from Egypt, and their shielding characteristics were estimated. Their rigidity, in addition to their elegant shape, led us to consider their use as a protective shield, in addition to making the workplace more beautiful. The mass attenuation coefficient (μ/ρ) was calculated for three types of marble (Breshia, Galala, and Trista) experimentally, using a narrow gamma ray source and high pure germanium (HPGe). The results obtained were compared with the XCOM program and indicated a very good agreement between the two methods. The linear attenuation coefficient (μ) was evaluated to calculate the half and tenth value layers. The maximum μ value of 1.055, 1.041, and 1.024 cm⁻¹ was obtained for Breshia, Galala, and Trista, respectively, at 0.06 MeV. The mean free path for studying the materials was compared with other shielding materials and showed good results at different energy scales. The energy absorption (EABF) and exposure buildup factors (EBF) were determined at different mean free paths. The fast neutron removal cross section Σ_R was calculated and expresses the ability of the marbles to slow down fast neutrons through multiple scattering. This is the ability of the marbles to shield fast neutrons.     

Stability,Energetic, and Reactivity Properties of NiPd Alloy Clusters Deposited on Graphene with Defects: A Density Functional Theory Study

Graphene with defects is a vital support material since it improves the catalytic activity and stability of nanoparticles. Here, a density functional theory study was conducted to investigate the stability, energy, and reactivity properties of Ni_nPd_n (n = 1–3) clusters supported on graphene with different defects (i.e., graphene with monovacancy and pyridinic N-doped graphene with one, two, and three N atoms). On the interaction between the clusters and graphene with defects, the charge was transferred from the clusters to the modified graphene, and it was observed that the binding energy between them was substantially higher than that previously reported for Pd-based clusters supported on pristine graphene. The vertical ionization potential calculated for the clusters supported on modified graphene decreased compared with that calculated for free clusters. In contrast, vertical electron affinity values for the clusters supported on graphene with defects increased compared with those calculated for free clusters. In addition, the chemical hardness calculated for the clusters supported on modified graphene was decreased compared with free clusters, suggesting that the former may exhibit higher reactivity than the latter. Therefore, it could be inferred that graphene with defects is a good support material because it enhances the stability and reactivity of the Pd-based alloy clusters supported on PNG.     

Destructive and Non-Destructive Evaluation of Fibre-Reinforced Concrete: A Comprehensive Study of Mechanical Properties

Ultrasonic pulse velocity (UPV) and rebound hammer tests are accepted as alternatives to destructive testing to determine the compressive strength, dynamic modulus of elasticity, and Poisson’s ratio, which are needed for structural design. Although much work has been conducted for plain concrete, the research data for fibre-reinforced concrete (FRC) is insufficient. In this regard, this study explains the correlations between compressive strength, rebound hammer, and UPV tests for plain concrete and FRC contains 0.25%, 0.50%, and 1.00% of 30 mm and 50 mm long steel fibres. A total of 78 concrete cube and beam specimens were tested by direct, semi-direct, and indirect UPV and rebound hammer test methods. The study found that the rebound hammer test is more suitable for measuring the compressive strength of matured FRC than young concrete. The UPV test revealed that the volume fraction does not, but the length of steel fibres does affect the UPV results by the direct test method. The UPV direct method has the highest velocity, approximately two times the indirect velocity in FRC. UPV measurements can be effectively used to determine the dynamic modulus of elasticity and Poisson’s ratio of FRC. The dynamic elastic modulus increases while the Poisson’s ratio decreases for the same steel fibre length when at increasing FRC fibre content. The results of this study will be significant for non-destructive evaluations of FRC, while additional recommendations for future studies are presented at the end of the paper.     

Comprehensive Diagnostic Assessment of Health Status of Patients with Asthma or COPD: A Delphi Panel Study among Dutch Experts

A comprehensive diagnostic assessment is needed to improve understanding of the health status of patients with chronic obstructive pulmonary disease (COPD) or asthma. Therefore, this study investigated which components and subsequent instruments should be part of a holistic assessment in secondary care. We also explored which data need to be exchanged for an adequate transfer of patients between primary and secondary care, and vice versa. A cross-sectional Web-based survey was conducted among Dutch healthcare professionals using a Delphi-like procedure; these included professionals working in primary or secondary care, medical advisors of health insurance companies and patients' representatives. The national guidelines were used as a starting point, resulting in a questionnaire addressing 55 components related to a comprehensive diagnostic assessment, covering the domains physiological impairments, symptoms, functional limitations and quality of life. Of the 151 experts and stakeholders invited, 92 (60.9%) completed the first round and 79 (52.3%) the second round; most respondents were pulmonologists. There was a high level of agreement between respondents from primary versus secondary care regarding which components should be measured during a comprehensive assessment of patients with asthma or COPD in secondary care and the instruments to measure these components. Regarding the exchange of information, upon referral, pulmonologists required little information from the general practitioners, whereas general practitioners required more extensive information after referral. An overview is provided of what should be part of a holistic assessment of health status in asthma and COPD. This information can be used as input for integrated care pathways.     

Mechanical Properties,Crack Width,and Propagation of Waste Ceramic Concrete Subjected to Elevated Temperatures: A Comprehensive Study

Waste ceramic concrete (WOC) made from waste ceramic floor tiles has several economic and environmental benefits. Fire is one of the most common disasters in buildings, and WOC is a brittle construction material; therefore, the mechanical properties of WOC structures under high temperatures should be considered. According to previous studies, hybrid fiber can further reduce damage to concrete under high temperatures. Meanwhile, crack width and propagation are among the key characteristics of concrete materials that need to be considered, but few studies have focused on their behavior when subjected to elevated temperatures. The new concrete materials proposed by the authors are WOC and WOC-Hybrid. WOC was prepared with Natural Coarse Aggregates (NCA), Natural Fine Aggregate (NFA), Ordinary Portland Cement (OPC 43 grade), and ceramic waste tiles with 20% replacements for coarse aggregates, 10% replacements for fine aggregates, and 10% replacement for cement. In contrast, WOC-Hybrid was prepared with the addition of hybrid fiber (1% crimped steel fiber and 1% polyvinyl alcohol fiber) in WOC. The specimens were exposed to temperatures of 100–300 °C, and then the specimens were tested for tensile and compressive strength. The present study aims to find a new method to improve concrete resistance to elevated temperatures at the lowest costs by experimental and computational analysis via machine learning models. The application of machine learning models such as artificial neural networks (ANN) and multiple linear regression (MLR) was employed in this study to predict the compressive and tensile strength of concrete. The linear coefficient correlation (R²) and mean square error (MSE) were evaluated to investigate the performance of the models. Based on the experimental analysis, the results show that the effect of hybrid fiber on the crack width and propagation is greater than that on the crack width and propagation of WOC and PC after exposure to high temperatures. However, the enhanced effect of hybrid fiber on the mechanical properties, rack width, and propagation decreases after subjecting it to a high-temperature treatment, owing to the melting and ignition of hybrid fibers at high temperatures. Regarding the computational analysis, it was found that the developed MLR model shows higher efficiency than ANN in predicting the compressive and tensile strength of PC, WOC, and WOC-Hybrid concrete.     

重组日本血吸虫26 kDa GST抗原免疫水牛后抗体动态及免疫保护性效果

目的　观察重组日本血吸虫 2 6kDaGST抗原 (reSjc2 6GST)免疫役用放养水牛 (简称水牛 )后抗体动态及免疫保护性的效果。　方法　试验组 96头水牛 ,用reSjc2 6GST免疫 3次 ,每次间隔 2wk ,3次剂量分别为 0 2、 0 2和 0 1mg。对照组 90头水牛不作免疫 ;观察 2组水牛免疫前及免疫后 2、 5、 9、 12、 15和 2 0个月的抗体水平及血吸虫感染率的变化。　结果　试验组机体产生特异性抗reSjc2 6GST抗体 ,其抗体水平呈明显的梯形升高趋势。试验组免疫后 2 0个月血吸虫感染率比免疫前下降了 62 2 % ,比同期对照组低 67 7%。　结论　用reSjc2 6GST免疫水牛能产生特异性抗体 ,在免疫后 2 0个月内维持较高水平 ,有一定的抗血吸虫自然感染的保护力。     

重组日本血吸虫26 kDa GST抗原免疫水牛后抗体动态及免疫保护性效果

目的　观察重组日本血吸虫 2 6kDaGST抗原 (reSjc2 6GST)免疫役用放养水牛 (简称水牛 )后抗体动态及免疫保护性的效果。　方法　试验组 96头水牛 ,用reSjc2 6GST免疫 3次 ,每次间隔 2wk ,3次剂量分别为 0 2、 0 2和 0 1mg。对照组 90头水牛不作免疫 ;观察 2组水牛免疫前及免疫后 2、 5、 9、 12、 15和 2 0个月的抗体水平及血吸虫感染率的变化。　结果　试验组机体产生特异性抗reSjc2 6GST抗体 ,其抗体水平呈明显的梯形升高趋势。试验组免疫后 2 0个月血吸虫感染率比免疫前下降了 62 2 % ,比同期对照组低 67 7%。　结论　用reSjc2 6GST免疫水牛能产生特异性抗体 ,在免疫后 2 0个月内维持较高水平 ,有一定的抗血吸虫自然感染的保护力。