Characterization and Gamma-ray Shielding Performance of Calcinated and Ball-Milled Calcinated Bentonite Clay Nanoparticles

The current investigation deals with the fabrication of two various composite-based bentonite clay minerals. The characterization and radiation shielding parameters for the two fabricated composites (calcinated and ball-milled calcinated bentonite) were studied. X-ray diffraction was utilized to illustrate the crystalline phase of the fabricated composites. Furthermore, Williamson and Hall’s method was used to determine the grain size of both the calcinated and ball-milled calcinated composites. The particle size, according to the calculation was 39.84 nm, and the strain was 0.216 for the calcinated bentonite, while the particle size of the ball-milled bentonite was 26.96 nm, and the strain was 0.219. In comparison, the transmission electron microscope (TEM) showed that the grain size of the calcinated bentonite was 566.59 nm, and it was 296.21 nm for the ball-milled calcinated bentonite. The density of the fabricated composites varied between 1.60 and 186 g/cm3 for the calcinated bentonite and between 1.83 and 2.075 g/cm3 for the ball-milled calcinated bentonite. Moreover, the radiation shielding capacity of the composites was analyzed. The results show that the gamma-ray attenuation capacity of ball-milled calcinated bentonite is high compared to ordinary calcinated bentonite. These results confirm the effect of particle grain size on optimizing the gamma-ray shielding capacity of the fabricated materials. © 2022 by the authors.Princess Nourah Bint Abdulrahman University, PNU: PNURSP2022R57The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R57), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia

The Role of La2O3 in Enhancement the Radiation Shielding Efficiency of the Tellurite Glasses: Monte‐Carlo Simulation and Theoretical Study

The radiation shielding competence was examined for a binary glass system xLa2O3 + (1 − x) TeO2 where x = 5, 7, 10, 15, and 20 mol% using MCNP‐5 code. The linear attenuation coefficients (LACs) of the glasses were evaluated, and it was found that LT20 glass has the greatest LAC, while LT5 had the least LAC. The transmission factor (TF) of the glasses was evaluated against thicknesses at various selected energies and was observed to greatly decrease with increasing thickness; for example, at 1.332 MeV, the TF of the LT5 glass decreased from 0.76 to 0.25 as the thickness increased from 1 to 5 cm. The equivalent atomic number (Zeq) of the glasses gradually increased with increasing photon energy above 0.1 MeV, with the maximum values observed at around 1 MeV. The buildup factors were determined to evaluate the accumulation of photon flux, and it was found that the maximum values for both can be seen at around 0.8 MeV. This research concluded that LT20 has the greatest potential in radiation shielding applications out of the investigated glasses due to the glass having the most desirable parameters. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast‐track Research Funding Program to support publication in the top journal (Grant No. 42‐FTTJ‐77)

Influence of Li2O Incrementation on Mechanical and Gamma-Ray Shielding Characteristics of a TeO2-As2O3-B2O3 Glass System

According to the Makishema–Mackenzie model assumption, the dissociation energy and packing density for a quaternary TeO2-As2O3-B2O3-Li2O glass system were evaluated. The dissociation energy rose from 67.07 to 71.85 kJ/cm3, whereas the packing factor decreased from 16.55 to 15.21 cm3/mol associated with the replacement of TeO2 by LiO2 compounds. Thus, as a result, the elastic moduli (longitudinal, shear, Young, and bulk) were enhanced by increasing the LiO2 insertion. Based on the estimated elastic moduli, mechanical properties such as the Poisson ratio, microhard-ness, longitudinal velocity, shear velocity, and softening temperature were evaluated for the investigated glass samples. In order to evaluate the studied glasses’ gamma-ray shield capacity, the MCNP-5 code, as well as a theoretical Phy-X/PSD program, were applied. The best shielding capacity was achieved for the glass system containing 25 mol% of TeO2, while the lowest ability was obtained for the glass sample with a TeO2 concentration of 5 mol%. Furthermore, a correlation between the studied glasses’ microhardness and linear attenuation coefficient was performed versus the LiO2 concentration to select the glass sample which possesses a suitable mechanical and shielding capacity. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program to support publication in a top journal (Grant no. 42-FTTJ-67)

Design and Gamma-Ray Attenuation Features of New Concrete Materials for Low- and Moderate-Photons Energy Protection Applications

We aimed, in this investigation, to prepare novel concretes which can be used in gamma-ray shielding applications. The experimental approach was performed using a NaI (Tl) detector to measure the concrete’s shielding features for different energies, ranging from 0.081 MeV to 1.408 MeV. The density of the fabricated concretes decreased with increasing W/C ratio, where the density decreased by 2.680 g/cm3, 2.614 g/cm3, and 2.564 g/cm3 for concretes A, B, and C, respectively, with increases in the W/C ratio of 0.4, 0.6, and 0.8, respectively. When the energy was elevated between 0.08 MeV and 1.408 MeV, the highest values were attained for concrete A, with values ranging between 0.451 cm−1 and 0.179 cm−1. The lowest half-value layer (Δ0.5) values were achieved for concrete C, where the Δ0.5 values varied between 1.53 cm and 3.86 cm between 0.08 MeV and 1.408 MeV. The highest Δ0.5 values were achieved for concrete A, where the Δ0.5 varied between 1.77 cm and 4.67 cm between 0.08 MeV and 1.408 MeV. According to this investigation, concrete A has the highest promise in radiation shielding purposes because it has the most desirable properties of the concretes studied. © 2022 by the authors.Princess Nourah Bint Abdulrahman University, PNU: PNURSP2022R57The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R57), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia

A Study of Ta2O5 Nanopillars with Ni Tips Prepared by Porous Anodic Alumina Through-Mask Anodization

The paper discusses the formation of Ta2O5 pillars with Ni tips during thin porous anodic alumina through-mask anodization on Si/SiO2 substrates. The tantalum nanopillars were formed through porous masks in electrolytes of phosphoric and oxalic acid. The Ni tips on the Ta2O5 pillars were formed via vacuum evaporation through the porous mask. The morphology, structure, and magnetic properties at 4.2 and 300 K of the Ta2O5 nanopillars with Ni tips have been studied using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The main mechanism of the formation of the Ta2O5 pillars during through-mask anodization was revealed. The superparamagnetic behavior of the magnetic hysteresis loop of the Ta2O5 nanopillars with Ni tips was observed. Such nanostructures can be used to develop novel functional nanomaterials for magnetic, electronic, biomedical, and optical nano-scale devices

Computational Models of Anaphora

Interpreting anaphoric references is a fundamental aspect of our language competence that has long attracted the attention of computational linguists. The appearance of ever-larger anaphorically annotated data sets covering more and more anaphoric phenomena in ever-greater detail has spurred the development of increasingly more sophisticated computational models; as a result, the most recent state-of-the-art neural models are able to achieve impressive performance by leveraging linguistic, lexical, discourse, and en- cyclopedic information. This article provides a thorough survey of anaphora resolution (coreference) throughout this development, reviewing the avail- able data sets and covering both the preneural history of the field and—in more detail—current neural models, including research on less-studied as- pects of anaphoric interpretation such as bridging reference resolution and discourse deixis interpretation