Journal of Radioanalytical and Nuclear Chemistry最新文献

This study presents a comprehensive investigation into the production of ¹³⁹Pr, encompassing both theoretical and experimental approaches. The theoretical aspect of the research involves an in-depth exploration of various excitation functions for potential reactions leading to the production of ¹³⁹Pr. Using the TALYS-1.9 code, a wide array of reactions involving different targets (Ce, La, Nd, and Pr) and projectiles (protons, deuterons, and alphas) was analyzed. The results from the TALYS code revealed that ¹⁴⁰Ce served as the most promising target. Subsequently, the SRIM code was employed to determine the optimal thickness of the ¹⁴⁰Ce target for the proposed reactions. In the experimental approach, the preparation of the target was done using tablet method, resulting in the creation of four disk-shaped tablets. These tablets were then subjected to irradiation with a proton beam in the energy range of 30 MeV. The outcome of this comprehensive study culminated in a substantial production yield of 34.2 mCi/u.A.h, demonstrating excellent agreement with similar experimental processes conducted by other researchers.

Uranium garners enough attention, not only as a high priority contaminant but also as the major infrastructure of nuclear energy systems. This review comprehensively discusses uranium(VI) capture by zeolite-based materials. Among various factors, pore size and pH play critical roles. Morphological control, surface modification and composite formation are effective to promote uranium capture. Mesoporous SBA-15 and MCM-41 with surface modification have uranium(VI) adsorption of 804.8 and 807.3 mg/g, and show prospects for uranium extraction from seawater. The updated understanding feeds back design of zeolite-based scavengers, which hopefully resolve the burgeoning energy demand and deteriorating ecological environment towards a sustainable society.

Graphite surface is modified in the present study using cetyltrimethylammonium bromide and the resultant material, graphite-CTAB is evaluated as an adsorbent for ⁹⁹Mo(VI) anions. The surface modification was confirmed through Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) surface area analysis. The introduction of CTAB onto the graphite surface resulted in the incorporation of positively charged quaternary ammonium groups (–N⁺(CH₃)₃), which significantly enhanced the adsorption capacity by enabling strong interactions with molybdate species. Batch adsorption experiments demonstrated that the optimal conditions for molybdenum adsorption occurred at pH 3. Equilibrium was rapidly attained within one hour, and an adsorbent mass of 0.1 g was found to be optimal. Adsorption efficiency decreased at higher ionic strength of the solution using NaCl. Desorption studies identified Na₂CO₃ as the most effective desorbing agent for recovering molybdenum from graphite-CTAB. Kinetic modeling of the adsorption data best fit the pseudo-second-order model, suggesting chemisorption. Furthermore, equilibrium data were well described by the Langmuir isotherm model, indicating monolayer adsorption on a homogeneous surface, with a maximum adsorption capacity of ⁹⁹Mo(VI) of 18.6 mg/g. Thermodynamic analysis revealed the process to be spontaneous, endothermic, and overall favorability of the adsorption process.

This study evaluates the radiological health risks associated with naturally occurring radionuclides (²²⁶Ra, ²³²Th and ⁴⁰K) in 10 breakfast cereal and 15 biscuit samples commonly consumed in Turkey. Activity concentrations were measured using a NaI(Tl) γ-ray spectrometer and ranged from 8.3 to 18.9, 4.1–16.4 and 49.1–125 Bq kg⁻¹, respectively. Estimated mean annual ingestion doses were 143 µSv y⁻¹ (children) and 130 µSv y⁻¹ (adults) from cereals, and 140 µSv y⁻¹ (children) and 127 µSv y⁻¹ (adults) from biscuits, all below the ICRP 1 mSv y⁻¹ limit. Average ELCR values were 1.8 × 10⁻⁴ (children) and 3.4 × 10⁻⁴ (adults) for cereals, and 1.0 × 10⁻⁴ (children) and 3.3 × 10⁻⁴ (adults) for biscuits, aligning with UNSCEAR estimates. Although risks are low, regular surveillance of food radioactivity remains important.

In prompt gamma neutron activation analysis, neutron self-shielding effects constitute a critical factor influencing the accuracy of quantitative elemental analysis. This study develops a neutron self-shielding correction method integrating Monte Carlo simulations with an optimization algorithm. Measurements were conducted using Cl as the target analyte with an Am-Be neutron source and a high-purity germanium detector. A functional relationship between Cl concentration and characteristic gamma-ray counts was established, and a leave-one-out cross-validation was applied. The concentrations of unknown samples were predicted via the optimization algorithm. The results demonstrate that the relative errors between predicted and reference values remain below 8%.

[¹³¹I]I-AMB10, a synthetic derivative of alpha mangostin, was developed to target estrogen receptor alpha (ERα)-positive breast cancer. Radiolabeled using iodine-131 via chloramine-T oxidation, it achieved high radiochemical purity (97.53 ± 1.08%). The compound exhibited moderate lipophilicity (log P = 0.67 ± 0.13) and plasma protein binding (73.66 ± 4.99%). Internalization studies revealed higher uptake in T-47D cells compared to MCF-7 cells, indicating selective affinity for ER + lines. Computational study of the compound showed high binding affinity and stability in the binding pocket of the ERα receptor. These results suggest that [¹³¹I]I-AMB10 has potential as a targeted theranostic agent for ERα-positive breast cancer.

Spent tributyl phosphate (TBP) dissolved in n-dodecane is a kind of radioactive organic waste that requires effective treatment in nuclear fuel reprocessing. This study optimized and evaluated the mineralization of TBP/n-dodecane using O₃/H₂O₂ advanced oxidation process. Under optimal conditions (pH 7.0, H₂O₂ dosage of 86.3 mL, O₃ concentration of 159.7 mg L⁻¹, and reaction time of 12 h), a mineralization efficiency of 96.6% was achieved, with a residual TOC of 759.0 mg L⁻¹. The results show that the reaction process conforms to a pseudo-first-order kinetics.

With the rapid expansion of the nuclear industry and growing emphasis on sustainable development, the extraction of uranium from seawater has garnered significant attention. Consequently, the development of highly efficient uranium adsorbent materials has become an urgent priority. This study delved deeply into the impact of regulating the surface positive charge density of layered double hydroxides (LDHs) on uranium extraction performance, using the LDHs-(Zn/Al) system as the subject of research for a series of systematic studies. The investigation selected Zn²⁺ and Al³⁺ as the layer cation combinations. By precisely regulating the Zn/Al molar ratio (ranging from 2:1 to 6:1) in the precursor, a series of LDHs-(Zn/Al) with regular crystal structures were successfully synthesized, and the layer composition was gradually adjusted. Adsorption experiments revealed that the maximum uranium extraction capacity in simulated seawater reached 31.15 mg/g. Furthermore, against a seawater backdrop, when the uranium concentration ranged from 3.3 to 100 ppb, the solid–liquid ratio is 0.25 g/L, and the uranium extraction efficiency exceeds 95%. These outstanding experimental outcomes suggest that this study offers a novel design strategy for creating efficient and stable uranium extraction materials from seawater, holding significant theoretical implications and practical potential.

Raman, FTIR, and diffuse reflectance spectroscopy were used to study the auto-radiolytic degradation of ²⁴⁰Pu and ²⁴²Pu oxalates. The significant differences in the lifetimes of ²⁴⁰Pu and ²⁴²Pu enabled the differentiation between environmental and radiolytic mechanisms. ²⁴⁰Pu oxalates were observed to decompose to PuOCO₃ at intermediate times (~ 20 weeks) followed by partial conversion to PuO₂ at times greater than one year. Atmospheric oxidation was shown to be the primary decomposition mechanism for ²⁴²Pu(IV) oxalate, and the alpha radiolysis of aquo and oxalate ligands serves as a secondary decomposition mechanism. This study offers a fresh perspective on radiolytic aging, which is crucial for long-term storage applications.

This study presents a comparative first-principles investigation of uranium hexafluoride (({textrm{UF}}_{6})) adsorption on two-dimensional group-IV materials—silicene, germanene, and stanene using density functional theory (DFT). The adsorption behavior was systematically analyzed at three distinct sites (P1, P2, P3) by calculating adsorption energies, equilibrium distances, charge transfer, and structural deformations. The results reveal that adsorption strength follows the trend stanene > germanene > silicene. Stanene exhibits the most favorable adsorption energy ((-1.680) eV), the highest charge transfer ((-0.676) e), and the most significant substrate distortion, indicating strong chemisorption driven by enhanced chemical reactivity, lower electronegativity, and larger atomic radius. Density of states (DOS) analysis further confirms the strongest orbital hybridization. These findings demonstrate that stanene is a superior candidate for ({textrm{UF}}_{6}) capture and sensing applications compared to its lighter analogues and graphene-based materials.