Atmospheric Nitrogen Plasma-Induced for Embedding NH2@Cubic-Bicontinuous Mesoporous Silica as Uranium (VI) Adsorbent Candidate in Seawater

This work aims to achieve interesting progress in uranium extraction by introducing a promising strategy that utilizes atmospheric nitrogen plasma-induced amine modification of CBC (Cubic Bi-continuous) material, providing a compelling pathway to enhance CBC's adsorption properties specifically for uranium harvesting. CBCs mesoporous silica samples were prepared by mixing the Pluronic F-127 as a template and TEOS (Tetraethyl Orthosilicate) as silica sources in the sol-gel process under acidic conditions. The obtained CBCs were treated using nitrogen plasma at room temperature (RT) under atmospheric pressure in a customized-borosilicate plasma reactor. Subsequently, the treated CBSs were grafted with amine groups. The final samples were characterized using SAXS (Small Angle Synchrotron X-ray Scattering) to determine the phase and structure, SEM-EDS (Scanning Electron Microscopy-Energy Dispersive Spectroscopy) analysis to quantify the presence of silica, oxygen, and embedded nitrogen, and Specific Surface Area (SSA) Analyzer using Brunauer-Emmett-Teller (BET) method to determine the specific surface area and pore size distribution. The SAXS profiles indicate that the obtained samples can be classified as CBCs Im3m mesoporous silica. The presence of silica, oxygen, and nitrogen was verified through SEM-EDS analysis, with approximate compositions of 36-37 %, 51-62 %, and 0.7-1.0 %, respectively. The use of SSA analysis further supported the findings, confirming the typical adsorption isotherm IV model. The specific surface areas were measured to be 371 m2/g for pure CBC, 573 m2/g for P1-CBC, and 607 m2/g for P2-CBC. The pore size distribution analysis revealed mesoporous characteristics within the material, with pore sizes ranging from 4 to 6.5 nm. On a batch laboratory scale, the material achieved the highest adsorption capacity of 15.68 mg-U(VI)/g-NH2@P1-CBC from natural seawater after 1 hour of contact time

Bibliometric Analysis of the Literature on Carbon Ion Therapy Using VOSviewer Software and Dimensions Database

This study aims to carry out a bibliometric assessment of the worldwide research literature and historical research results on carbon ion therapy for cancer treatment. To carry out this work, we used the VOSviewer software and the Dimensions database. The VOSviewer software tool examined 2,500 publications exported from the Dimensions database. The results show a notable upward trajectory in academic research on carbon ion therapy since 1994, with 2020 showing the highest volume of publications. “Biomedical and Clinical Sciences”, “Physical Sciences”, “Oncology and Carcinogenesis”, and “Medical and Biological Physics” are the most important research categories. “Physics in Medicine and Biology” and “Medical Physics” are the leading journals for research publications on carbon ion therapy. Scrutiny based on term occurrences demonstrates the shift in research interest towards carbon ion radiation therapy. The analysis of bibliographic couplings concerning different countries revealed that Japan is the most dynamic and prolific country based on the number of publications (659) and citations (13734), followed by Germany with 590 publications and 19679 citations. These analytical studies provide a thorough overview of academic publications dedicated to using carbon ions for tumor treatment. This data is anticipated to be highly valuable for researchers seeking to pinpoint the most recent developments and emerging trends in this field of research

Weighted CTDI Equation for 3D Rotational Angiography: A Monte Carlo Study

This study aims to verify the weighted Computed Tomography Dose Index (CTDIw) coefficients of 3D rotational angiography (3DRA) procedure using Monte Carlo simulation. The Monte Carlo simulation EGSnrc usercode was employed for 3D dose simulations of the rotational angiography procedure. A virtual phantom resembles the head CTDI phantom was constructed, with a diameter of 16 cm and a density resembling polymethyl methacrylate (1.13 g/cm3). A series of virtual phantoms consisting of 5 images with ionization chamber detectors at the center position, 12 o'clock, 9 o'clock, 6 o'clock, and 3 o'clock were acquired. Simulations were performed with photon sources of 70 and 109 kVp for 200-degree x-ray tube rotation. The field of view was divided into narrow, wide, and full beam with diameters of 1.7 cm; 4.9 cm; and 8.6 cm, respectively. The simulated doses at the ionization chamber were processed into weighting factor for weighted CTDI and compared with direct measurements. The dose ratio between peripheral and center positions for 360° CBCT and 200° 3DRA was 1:1 and 1:3 in this study. The weighting factors for 3DRA were determined as CTDIcenter = ¼ and CTDIperiphery = ¾. The measured average percentage difference of CTDIw between our weighted factor and conventional CTDIw was 1.75 % (-3.99 % to 6.08 %). The x-ray tube position of 3DRA impacted the accuracy of weighting factor of CTDIw, with implications for the proposed weighting factor (Wcenter = ¼ and Wperiphery = ¾) when using a 3DRA machine

Modeling of 137Cs Dispersion in the Atlantic Ocean at Ahanta West Coast: A Hypothetical Candidate Site for Ghana’s First Nuclear Power Plant

The government of Ghana has the intention of adding nuclear to its energy mix. Due to water availability for cooling, the coastal areas will be the right place for siting a nuclear power plant. This study was carried out to assess the distribution of 137Cs should liquid radioactive waste be released into coastal waters because of a non-routine event. The distribution was studied for the first month after the release. In the first week following the release, 137Cs was distributed within 16 km of the Ahanta West coastal waters with a concentration of about 9.1 Bq. L-1. On the seventh day, the distribution reached the entire coast of the Nzema East with a lower concentration with the bulk of the concentration still in the Ahanta waters. The 137Cs continued to spread into the eastern coast until the thirty-first day with a concentration of less than 1 Bq. L-1. This study provides useful data for future monitoring along the coast

Neutronic Design Modification of Passive Compact-Molten Salt Reactor

Passive compact molten salt reactor (PCMSR) is a design concept of a molten salt reactor (MSR) currently under development in Universitas Gadjah Mada, Indonesia. It is designed as a thermal breeder reactor using thorium fuel cycle. However, our previous study shows that the original PCMSR design was incorrectly modelled, primarily overestimating its thorium breeding capability. To improve PCMSR neutronic design, we modified the core configuration by the addition of radial fuel channel layers previously nonexistent in original PCMSR core design in various configurations. Neutronic parameters of modified PCMSR geometries in the beginning of life (BOL) were simulated using MCNP6.2 radiation transport code with ENDF/B-VII.0 library. All variations of fuel layer addition show improvement in both temperature coefficient of reactivity (TCR) and breeding ratio (BR), with TCR values became more negative and BR values are larger than unity, ensuring proper breeding capability. Configuration Inner Core-Outer Blanket (IC-OB) achieves the largest BR and lowest doubling time (DT), whilst its TCR is an improvement from the original design. Therefore, IC-OB fuel layer configuration can be applied to redesign the original PCMSR and used in various design optimization scenarios

Non-Dimensional Number Analysis on Natural Circulation Flow Changes Inside Straight-Pipe Heat Exchanger of Water Cooling Tank in FASSIP-02 Test Loop

The FASSIP-02 test loop is a large-scale experimental facility that investigates natural circulation flow rate phenomena to improve passive safety systems of nuclear reactors. Heat transfer in the piping system will result in pattern and magnitude of the natural circulation flow being formed, so it is essential to investigate the heat dissipation capabilities, which will later be applied in nuclear passive cooling systems. The heat transfer behavior of passive cooling systems in large-scale facilities can be quantified with non-dimensional numbers. This research analyzes heat transfer in a straight heat exchanger by comparing non-dimensional numbers based on the Dittus-Boetler and McAdams correlation with the correlation generated from experimental data. The analysis results show that the predicted McAdams correlation with the experimental correlation is higher than 83 %. Meanwhile, Dittus Boetler's correlation prediction with the experimental correlation is smaller than 71 %. The dominance of momentum diffusivity in the cooling process shows the characteristics of thermal behavior with the Prandtl number. In addition, all-natural circulation flow variations occur in a turbulent flow regime that increases with increasing water temperature in the heating tank