Volume 112, Issue 11

Independent isomeric yield ratios (IR) of 128,130,132 Sb, 131,133 Te, 132,134 I, 135 Xe and 138 Cs in the epi-cadmium neutron-induced fission of 245 Cm have been measured for the first tim e by using an off-line gamma-ray spectrometric technique. The average energy of the epi-cadmium neutron spectrum (< E n >) is 1.9 MeV. From the IR values, root mean square fragment angular momenta ( J RMS ) were deduced by using the spin dependent statistical model analysis. The IR and J RMS values of the fission products from the present work were compared with the literature data in the thermal neutron-induced fission of 245 Cm to examine the role of excitation energy. Effect of nuclear structure on J RMS value was also examined.

This work synthesized MnO 2 modified winter melon-derived biochar (MnO 2 @WBC) using potassium permanganate oxidation/hydrothermal method for uranium(VI) removal. The factors influencing uranium(VI) adsorption by MnO 2 @WBC, including pH, adsorbent dosage, time, temperature, and initial U(VI) concentration were explored. The material’s performance was characterized, and the underlying mechanism of U(VI) removal was analyzed using various techniques. The characterization results indicated that the MnO 2 @WBC exhibited excellent dispersibility, suggesting that MnO 2 effectively prevented WBC aggregation and enhanced the reactive surface area, and providing more active sites that can effectively promote the complexation and adsorption of U(VI). The process suggested a dominant role for chemical adsorption. The Freundlich isotherm model demonstrated a high degree of alignment with the observed adsorption behavior, indicating a predominantly multilayer adsorption process. Thermodynamic studies indicated that adsorption was a spontaneous endothermic process. The XPS analysis demonstrated that the adsorption process was primarily due to the formation of stable complexes with C–O, Mn–O–H and C=O. The results demonstrated that MnO 2 @WBC effectively removed U(VI), achieving a maximum adsorption capacity of 240.86 mg g −1 at a pH of 5.0. These findings provided a theoretical basis for the treatment of wastewater contaminated with U(VI).

In this study, three starch hydrogels composite prepared using different ratios of starch, citric acid, acrylamide, and MgO nanoparticles (referred to as St 1 -g-(CA-AM), St 2 -g-(CA-AM), and St 3 -g-(CA-AM) MgO). These materials were assessed using FT-IR, SEM, and EDX. The adsorption of  134 Cs(I) and 60 Co (II) onto these materials studied using radiometric analysis. The investigation focused on how temperature, contact duration, initial metal ion concentration, and pH of the solution affected the sorption efficiency. It is found that a pH value of 7 optimized the adsorption reaction, reaching equilibrium after 40 minutes. The kinetics of the adsorption followed a pseudo-second order model. The Langmuir model adequately explained the sorption mechanism, supported by the analysis of isotherm models. The monolayer adsorption capacities for 60 Co (II) and 134 Cs (I) were 113.38 and 100.2 mg g −1 , respectively. The thermodynamic study indicated that the sorption process is both endothermic and spontaneous.

The radionuclides 60 Co and 54 Mn are the main activation products produced in the operation of nuclear power facilities. Wastewater with these radionuclides must be treated to meet standards before being discharged. A variety of zeolite imidazole frameworks (ZIFs) materials were synthesized at room temperature, and the adsorption effect of ZIF-67 was found to be the best through adsorption experiments on Co(II) and Mn(II). The thermal stability test and structural characterization of ZIF-67 were carried out. At the same time, the influence of the initial pH value, adsorption time, and initial concentration of the solution on the adsorption of Co(II) and Mn(II) by ZIF-67 was investigated. The results show that: ZIF-67 has a microporous structure with a BET surface area of 1,035.72 m 2 /g. In addition, ZIF-67 has good thermal stability, under the condition of pH = 6, a temperature of 303 K and the initial concentration of 500 mg/L. The saturated adsorption capacity for Co(II) and Mn(II) reached 230.25 mg/g and 338.75 mg/g, respectively. ZIF-67 exhibits good selective adsorption performance for Co(II) and Mn (II) in high concentration interfering ion solutions and multi-ion solutions. The adsorption process of ZIF-67 was analyzed by kinetics, thermodynamics, isotherms, and adsorption diffusion models. The analysis of thermodynamic parameters shows that the adsorption process of ZIF-67 to Co(II) and Mn(II) is spontaneous and endothermic. The pseudo-second-order kinetic model, Langmuir isotherm model, and Boyd model are more in line with the adsorption process of Co(II) and Mn(II) by ZIF-67. It shows that the active sites on the surface of ZIF-67 are evenly distributed, and the adsorption process is single-molecule chemical layer adsorption. In addition, the liquid film diffusion dominates the adsorption rate during the adsorption process of Co(II) and Mn(II) by ZIF-67.

Recently, tumor-targeted radionuclide therapy has gained much recognition for the treatment of metastasized cancer. There is a growing interest in using the theranostic radionuclide 47 Sc, owing to its excellent chemical and nuclear properties. However, the available chelating agents require a relatively high temperature for their radiolabeling, which could denature biomolecules. The aim of the present study is to synthesize a dipeptide agent that forms a thermodynamically more stable complex with 47 Sc at room temperature. A novel α -amino acid ester derivative attached to pyrazine and tetrazole heterocyclic rings has been prepared by the azide coupling method. Different spectroscopic methods (FT-IR, 1 H NMR, and mass spectra) were used for characterization of the target compound. The newly synthesized dipeptide was radiolabeled with 47 Sc, and a high radiochemical yield of 98.5 ± 1.5 % and in vitro serum stability up to 72 h were attained at room temperature within 20 min. The quantum chemical calculations at B3PW91/6-31G(d) level were employed to establish the molecular structure of the dipeptide and its complexation with 47 Sc. The selectivity of 47 Sc-dipeptide toward localization in tumor cells was performed by molecular docking on different receptors in addition to in vivo biodistribution on solid tumor-bearing mice. A high T/NT ratio of 8.16 was obtained after 4 h p.i, suggesting that this complex could be used as a potential cancer theranostic agent.

The prevalence rate of prostate cancer is very high and unfortunately causes many deaths worldwide. This study aimed to prepare [ 113m In]In-PSMA as a novel agent for single photon emission computed tomography (SPECT) imaging of prostate cancer. 113m In was eluted from an in-house made 113 Sn/ 113m In generator in chloride form, and its radionuclide, chemical and radiochemical purities was studied. [ 113m In]In-PSMA was prepared with radiochemical purity (RCP) > 99 % under optimal labeling conditions. The biodistribution of the labeled compound was studied in normal rats, showed the major activity in the urine and kidneys as the main excretion route from the body. Considerable uptake was observed in the prostate and salivary glands as the PSMA-expressing organs. These data are in complete agreement with the other published data on PSMA-labeled compounds both in animals and humans. The results demonstrated [ 113m In]In-PSMA can be considered as a good option for SPECT imaging of prostate cancer.

A multiscale model describing the kinetics of the processes taking place during the radiolysis of uranium hexafluoride (UF 6 ) has been developed using fundamental physical and chemical principles. The model incorporates both the radiolysis and thermal terms. The processes of the radiolysis products release from the gas phase to the solid and vice versa are taken into account. The predictions of the model are verified against the available experimental data.

Innovative solutions are needed to reduce the amount of high-level waste generated by used nuclear fuel recycling strategies to support the widespread adoption of sustainable nuclear fission energy technologies. To this end, a new sulfur chloride-based process has been developed to recycle zirconium alloy-based materials, which make up a significant fraction of high-level radioactive waste. To support the continued development of this process, we present new data on the potential reaction pathways over time of the products arising from the gamma and electron beam radiolysis of neat thionyl chloride (SOCl 2 ). Interrogation of the gamma irradiated liquid by Raman spectroscopy provided more conclusive identification of the SOCl 2 degradation products, specifically sulfur dichloride (SCl 2 ), molecular chlorine (Cl 2 ), sulfur dioxide (SO 2 ), and sulfuryl chloride (SO 2 Cl 2 ). In comparison, the high dose rate (∼10 7  Gy s −1 ) electron beam irradiations formed significantly more degradation products. For both cobalt-60 gamma and electron beam irradiations, the observed degradation products were found to evolve as a function of time post-irradiation via the same reaction pathways, with indication of a solvent regeneration mechanism. These findings are fortuitous for process development, as such a mechanism would be beneficial for process longevity and cost effectiveness.

The present study investigates gross alpha (GA) radioactivity levels in hazelnut kernels purchased from markets in Türkiye. 10 different hazelnut samples were crushed and made ready for counting. The alpha counts were obtained via ELSEC 7286 low level alpha counter with ZnS scintillator and EMI 6097B photomultiplier tube. The samples were placed in front of the detector to acquire the counts. All samples were counted isochronously. In addition to the GA activity measurement, total annual effective dose (AED) value for different age groups owing to ingestion was calculated for each sample. It was observed that the GA radioactivity levels in the samples were quite low, and total AED values were considerably lower than the WHO worldwide average AED value (290 μSv/year).

Fricke gel dosimeters are appropriate candidates for gamma dosimetry. Polyvinyl alcohol Fricke gel dosimeters are the most recent introduced gel dosimeters which have low ion diffusion. In this work, samples of ferrous-xylenol orange-polyvinyl alcohol gel dosimeters were prepared and characterized using optical spectroscopy. Using win XCOM program and the elemental composition of the gel, the mass attenuation coefficients for photons were evaluated. The results exhibited that the prepared gel is the nearly radiological blood-, soft tissue- and water-equivalent. The 60 Co gamma cell unit was used to irradiate the gel samples. A dose range response was found linear from 10 to 30 Gy and suitable for blood irradiation dosimetry. Additionally, the gel response good repeatability was confirmed by the coefficient of variation calculations. Furthermore, chemical yield of the gel was estimated to be 34.6. The good characteristics of the prepared gel make it appropriate for dosimetry of blood irradiators.