Abstract In this study, the ion exchange process of cerium and yttrium using Dowex 50W-X8 resin was investigated, and the behavior of the breakthrough curves was reported. The ion exchange percentage for Ce(III) and Y(III) was 73.93% and 70%, respectively. Mathematical modeling was performed to calculate the mass transfer components. Various mass transfer resistance mechanisms such as film diffusion resistance, intraparticle diffusion, axial dispersion, and other mass transfer approximations were investigated using the linear driving force (LDF) model. Investigations showed that intraparticle diffusion resistance had the largest contribution to the ion exchange process of the rare elements cerium and yttrium (Rf < Rax < Rint). Intraparticle diffusion, the second stage of the overall ion exchange mechanism, was identified as the controlling stage of the process. The Biot number for Ce(III) and Y(III) was greater than 30, indicating that the rate-controlling step of the ion exchange process was intraparticle diffusion, confirming the accuracy of the studies. The Peclet number also matched the slope of the breakthrough curves well.

Abstract Iodine-123 radionuclide was produced by bombarding a xenon-124 gas target with protons at an energy of 28.5 MeV in a cyclotron accelerator. After confirming the quality control procedures, the iodine-123 radionuclide, with a purity of over 99% and an activity concentration of 8.47 ± 0.2 GBq/mL, was used to label the MIBG chemical compound. Quality control of the labeled compound was conducted using thin-layer chromatography with acetic acid:water:butanol (1:1:4) as the mobile phase. The results of the quality control showed a radiochemical purity of over 99% for the final product. The biodistribution of the radiolabeled compound was assessed by injecting 5.5–11.1 MBq of the ¹²³I-MIBG radiopharmaceutical into rats. The rats were then dissected at various time intervals, and imaging was performed. A comparison of the biodistribution of free ¹²³I and ¹²³I-MIBG indicated that the radiolabeled compound exhibited a distinct biodistribution pattern compared to free ¹²³I.

Abstract In this study, we investigated the accurate diagnosis and differentiation of healthy and cancerous brain tissues using laser fluorescence imaging guided by the sodium fluorescein exogenous fluorophore. The results were compared with tissues' auto-fluorescence images. Samples, diagnosed as meningioma, metastatic carcinoma, low-grade glioma, and high-grade glioma types by pathologists, were obtained from four patients. An optical imaging technique with hematoxylin-eosin staining was used to validate the results. The findings revealed that the intensity of fluorescence radiation from cancerous tissues is more intense than that from healthy tissues due to the greater permeability of the dye in the cavities and pores of the tissue. This imaging method not only increases the accuracy and precision of the results but also allows the surgeon to visualize and diagnose the tumor in real-time and completely resect it, eliminating the need for invasive biopsies. Therefore, the results indicate that sodium fluorescein can be used as a reliable fluorescence marker in intraoperative imaging to improve the diagnosis and delineation of brain tumors.

Abstract An anodic electrophoretic method was utilized to create a uniform thin film coating on thin steel plates. The changes in the contact angle of the plates were carefully measured. Subsequently, the samples were subjected to testing in a boiling pool to measure the critical heat flux and the boiling heat transfer coefficient.  For the numerical simulation of plates with varying wettability, the critical heat flux was calculated for variable contact angles after validation. This was achieved by adjusting certain boiling parameters to values dependent on the contact angle. The results of the experimental tests and numerical simulations are closely aligned, displaying a similar trend.  Furthermore, a comparison between these results and other experimental data revealed a difference of less than 5%.

Abstract Nickel-based alloys are highly regarded for their strength and good corrosion resistance at high temperatures. Among nickel-based superalloys, the Ni-12.5Mo-7.8Cr alloy has garnered attention from researchers due to its low production cost, accessibility, excellent weldability, and resistance to hot corrosion. This study focuses on the microstructural changes induced by hot rolling on the mechanical properties and fracture behavior of the Ni-12.5Mo-7.8Cr nickel-based superalloy. To conduct the research, a hot rolling operation at 1100°C was carried out on a homogenized ingot previously heated at 1177°C for 20 minutes. Microstructural investigations, fracture behavior analysis, and mechanical property testing were conducted using optical and electron imaging techniques, as well as tensile tests. The microstructural analysis revealed the formation of both coarse and fine grains, resulting in an inhomogeneous structure post-hot rolling. The tensile test results indicated an approximately 120% increase in yield strength and a 13% decrease in final tensile strength due to hot rolling. Furthermore, the fracture pattern of the homogenized and rolled sample displayed a shift in fracture mechanism from ductile to grain boundary brittle as a consequence of hot rolling.

Abstract Positron Emission Tomography (PET) is an advanced tool used for diagnosing and staging cancer, based on detecting glycolytic activity in malignant cells. This method requires drugs like Fluorine Deoxy Glucose (FDG), which is produced by separating Fluorine-18 and Oxygen-18 isotopes with a purity level of over 95%. The use of cryogenic distillation columns to produce enriched oxygen is significant, despite the challenges of cost and efficiency. This study examines the optimization of distillation column performance by analyzing factors such as input temperature and pipe height using MATLAB software. The results show that the maximum separation of the desired isotope depends on the isotope type and apparatus conditions, while the feed type has no impact on concentration distribution. These findings can help improve methods for producing isotopes needed in medical imaging.

Abstract The radioactive gas radon infiltrates enclosed spaces through building materials and soil, and its accumulation in buildings with insufficient ventilation can pose health risks to occupants. This study aims to evaluate the effectiveness of natural ventilation in reducing radon concentration in apartment units. In this research, the impact of ventilation rate and building interior geometry on airflow patterns and radon concentration in an apartment unit was analyzed using computational fluid dynamics (CFD), and the simulation results were compared with experimental data. The simulation results indicated that the behavior of airflow and the location of radon accumulation under different ventilation rates are not precisely predictable. Despite the reduction in average radon concentration with increased ventilation rates, the formation of vortices in specific areas leads to localized radon concentrations several times higher than the average value. These findings highlight the limitations of natural ventilation in establishing a stable and uniform airflow pattern to fully expel radon from all areas of the indoor space. The results suggest that combining natural and mechanical ventilation strategies can be an effective approach to reducing radon concentration across all regions of an apartment unit.

Abstract One of the main challenges in proton computed tomography is the reduction of spatial resolution in the image due to the multiple Coulomb scattering of protons as they pass through the material. To address this issue, it is essential to model the most probable path of protons. Artificial neural networks, as an innovative solution in the field of machine learning, have played a key role in improving the accuracy of estimating the most likely path of protons. In this study, an artificial neural network utilizing an adaptive moment estimation optimization algorithm was developed to estimate the most likely path of protons. The network was trained using data from simulations of the proton computed tomography system in Geant4. Specifically, 60% of the data was used for training, 20% for validation, and 20% for testing the model. This data included information such as the entrance and exit positions of the protons, energy deposition, proton exit angle, and 10 path points for each proton. The sinogram matrix was adjusted using the estimated most likely path from the neural network and the cubic spline path, with image reconstruction performed using the Filtered Back Projection algorithm. The results of the study indicated that the network estimated most likely path method achieved a spatial resolution of 6-line pairs/cm, compared to 5-line pairs/cm for the cubic spline path method. Additionally, the root mean square error was calculated for both methods, resulting in 13.5% for the network estimated most likely path method and 15.95% for the cubic spline path method.

Abstract The Target Normal Sheath Acceleration (TNSA) method is one of the most efficient techniques for laser ion acceleration. One of the main challenges in optimizing this method is the detrimental impact of laser pre-pulses on the target, which can lead to plasma formation and changes in material density and temperature, resulting in shock wave formation and reduced acceleration efficiency. This study investigates the effects of laser Amplified Spontaneous Emission pre-pulse duration and intensity (ASE) and target material on the formation and propagation of shock waves in the proton acceleration process via the TNSA method. The numerical results and one-dimensional hydrodynamic simulations indicate that, at lower ASE intensities (around 1011W/cm2 and durations of 1 to 2 nanoseconds), the aluminum foil target undergoes minimal displacement, and due to the lack of deformation at the target’s rear side, It is expected that due to the lack of deformation at the target’s rear side, ion acceleration performance will not degrade. However, as the pre-pulse intensity increases, especially in lighter materials such as CH polymer, density variations and target displacement become more pronounced, which reduces the acceleration efficiency. These findings provide a basis for determining optimal conditions for laser acceleration experiments.

Abstract In this article, the structure and performance of the designed and constructed laser facility to perform basic research on the field of inertial confinement fusion and laser-plasma interaction have been studied. The laser facility has four laser beams and the optical amplifiers are based on the phosphate Nd:Glass solid-state active medium. The vacuum spatial filters have improved the beam quality and reduced the misalignment sensitivity of the optical structure. More than 30 Joules per beam have been achieved, and the total optical energy of the laser facility exceeds 120 J. The laser facility is upgraded to increase laser optical energy to 500 J. Temporal pulse-shaping of the laser master oscillator, the optical self-alignment systems, and equalization of the propagation time of laser beams from the laser source to the target position based on the heterodyne interferometer, are the main activities to make the implosion experiments of the pellets filled with the heavy isotopes of hydrogen for studying the inertial confinement fusion.