Ali Al Dabbas

The current study illustrates the modeling of a biocompatible poly γ-glutamic acid (PGA)–chitosan–rGO nanocomposite hydrogel scaffold, which showed a promising novel scaffold for stimulating central nerve regeneration that addresses the shortcomings of recent therapies and improves tissue engineering, controls inflammation, and restores lost functions after spinal cord injuries (SCIs). In the implementation part of the study, the COMSOL program’s top-notch modeling of a detailed investigation of how a scaffold’s in vivo diffusion affects injured neurons. Michaelis–Menten kinetics is used to characterize the enzyme process of releasing the outer covering shell of the scaffold, PGA, from a biomaterial matrix to the nerve cell. Results suggested that the injectable hydrogel scaffold theoretically reduces extracellular glutamate concentrations, presenting a potential mechanism to mitigate localized excitotoxicity. Future in vivo experimental validation is required to determine if this reduction prevents neural cell death

High-Efficiency Particulate Air (HEPA) filtration plays a crucial role in maintaining air quality in critical environments such as lean rooms, hospitals, and nuclear facilities. The point of this study is to look into how well nuclear-grade HEPA filters work and behave by looking at the main ways they catch particles using two modeling methods to figure out how well the filters work overall. This study encompasses particles with diameters ranging from 0.05 to 5.00 µm and a density of 1500 kg/m³. The current study systematically examined key parameters such as particle size, fiber diameter, and filtration velocity, which revealed their significant influence on the HEPA filter efficiency. Notably, the most penetrating particle size (MPPS) is identified within the expected range of 0.1–0.3 µm for both approaches. A critical threshold in fiber diameter is discovered when it exceeds 0.85 µm, resulting in a substantial shift in particle penetration and overall collection efficiency. This study also explored the impact of filtration velocity on filter performance, demonstrating increasing deviations as velocity rises, following a polynomial trend. The current study also rigorously validated the model predictions against experimental data from uranine particle filtration tests, confirming the model’s accuracy and applicability. These findings provide essential insights for optimizing the design and operation of nuclear HEPA filters, emphasizing the necessity of considering the particle size, fiber diameter, and filtration velocity. Both modeling approaches exhibit a negligible 0.04% deviation in the MPPS efficiency, which increases polynomially with the filtration velocity. Importantly, both approaches consistently identified the same MPPS regardless of the filtration velocity. Additionally, the model reinforces the substantial impact of fiber size on filter efficiency. A comprehensive comparison with the experimental data yielded closely aligned results with a maximum deviation of 1.14%. This validation strengthens the model’s ability to elucidate the underlying physical phenomena governing the influence of filtration velocity on efficiency, making it a valuable tool in nuclear HEPA filter research and development.

Contact with groundwater in the disposal geological site will induce the creation of an amorphous corrosion layer on the high-level radioactive glass. This is connected to silicate saturation conditions in the surrounding medium, and it is influenced significantly by geochemical processes in the near-field minerals at that depth. The international simple glass is a six-oxide borosilicate glass that is commonly used in nuclear interest. It is a simple glass generated from its composition to be an international benchmark glass. The results of the standard materials characterization center leaching tests in double deionized water at 90 °C and an initial pH value of 6.3 showed that it reacts with Ankerite for a short period of time. The effect of Ankerite on borosilicate glass durability through magnesium-silicate precipitation has been investigated and confirmed in this study.

In this study, the vitrified High-Level Radioactive Waste (HLW) disposal was simulated using a simplified version of the French R7T7 reference glass, called International Simple Glass (ISG). Test for nuclear waste form (MCC-1) was assembled for (3-90 days) using coupon samples of ISG and powdered Ankerite. Set up systems were conducted using ultrapure water at 90 °C and initial pH 6.3. The chemical effect of Ankerite on the ISG coupon was seen via Mg-Si precipitation, but the hydrated layer on the ISG was seen clogged by the Ankerite's dissolution products which lowered the ISG corrosion rate comparing to the ISG reference system. When the values expressed as mass glass dissolved per unit area, the higher sodium releases and the higher corrosion rates have been attained based on sodium release, which suggests sodium as representative of the ISG at the lower surface area to volume.

This work represents the potential impact of geological deposition conditions on the durability of glass used for radioactive waste disposal. The durability of highly radioactive glass could be influenced by iron mineral compositions or other near field parameters inside the final disposal repository. In this paper, silicate sorption by natural ankerite is experimentally studied. Preliminary study using the graphite furnace atomic absorption method to measure the change in concentrations of silicon in standard solution in the presence of natural ankerite was performed. All standard solutions were diluted from a saturated silicate stock solution. Natural ankerite mineral samples which were collected from Rudabánya, Hungary, showed strong sorption of (H4SiO4) on their interface. Batch experiments containing specific masses of natural ankerite and silicate solution were carried out in order to illustrate a better understanding of silicate reduction in solution due to the sorption mechanism of ankerite, evidence that ankerite has the ability to uptake silicate was seen. The desorption of adsorbed silicate was tested and it was noticed that only very small amounts of silicate returned to the solution showed tiny reversed concentrations of silicate which may an indication of chemisorption.