Journal of Radioanalytical and Nuclear Chemistry最新文献

As an energy-saving and facile technology, electrosorption technology has good potential in the process of separation of uranium from aqueous solution. In this study, sucrose and urea were used to prepare nitrogen-doped carbon by one-step carbonization, and polyacrylamide modified nitrogen doped carbon (PAM/NC) was obtained by modification. The electrosorption test results indicated that PAM/NC-2 had the best properties and the maximum electrosorption capacity was 619.5 mg g⁻¹. The performance loss was less than 20% after 5 adsorption–desorption cycles. Overall, this material had a potential application in U(VI) pollution remediation, meeting the need for sustainable development of nuclear energy.

The preliminary role of [¹⁸F]fluoro-5α-dihydrotestosterone ([¹⁸F]FDHT) in identifying receptor status and managing cancer patients is promising. In this work, we compiled studies regarding the ability of [¹⁸F]FDHT to predict response to treatment in different stages of drug development. In the chemical development, the androgen receptor (AR) ligands of [¹⁸F]FDHT were the candidates evaluated and identified using preclinical methods. High uptake of [¹⁸F]FDHT levels was observed in cell lines and xenograft tumours in mice having glucuronidation-competent cells mimicking the sensitive type of castration-resistant prostate cancer (CRPC) treated with androgen deprivation therapy (ADT). In clinical trials, the detection of lesions with [¹⁸F]FDHT was in agreement with the standard radiotracer [¹⁸F]FDG in advanced prostate cancer (PC) and was even better in AR-positive without glycolytic activity (AR₁Glyc₀) subtypes, demonstrating the specific role of [¹⁸F]FDHT for the detection of tumour localisation. Moreover, the immunohistochemistry (IHC) correlation between [¹⁸F]FDHT and AR was stronger than the correlation between [⁶⁸ Ga]Ga-PSMA-11 and prostate-specific membrane antigen (PSMA), suggesting that [¹⁸F]FDHT can be a standalone modality for the monitoring of AR-targeted therapy.

The elemental composition of coral skeletons supplies essential information about palaeoceanographic reconstructions. The present work aims to optimize the neutron activation analysis (NAA) protocol for determining Ca-substituting elements in coral skeletons, which can be considered as a potential indicator for reconstructing past climate variability. Conventional and epithermal NAA schemes have been applied to determine 22 elements. The results reveal that the use of epithermal NAA significantly improved the limits of detection, up to 10 times, for specific elements, e.g. As, Ba, Cd, Mn, Sr, etc. The Compton suppression counting regime yielded an additional improvement in the limits of detection.

This paper explores the correlation between soil radon and thoron concentrations and seismic events at Chite fault in Aizawl over a three year period using SSNTDs. The data analysis was done using STL method which decomposes a time series into three components: seasonal, trend, and remainder. Elevated residual concentrations of these gases were observed prior to the M5.4 earthquake that occurred at a distance of 123.9 km from the monitoring station, suggesting a potential link between gas emanation and seismicity. The results of the study demonstrated the effectiveness of the STL method in detecting anomalies in diverse time series datasets.

A new polymer hyrogel dosimeter based on acrylic acid in polyvinyl alcohol hydrogel matrix was prepared to be used in radiation measurments for radiotherapy treatment. The hydrogel dosimeters were exposed to ionizing radiation using a medical linear accelerator. The hydrogel samples were irradiated at 6 MV beam energy, 600 cGy min⁻¹ dose rate, and various doses up to 50 Gy. UV–VIS Spectrophotometry was used to readout the dose response of non-irradiated and irradiated hydrogel samples at absorbance of 630 nm. The results show the dose response increases strongly with increasing abosrbed doses, with a large linear dose range (2–30 Gy) and dose sensitivity of 0.013 Gy⁻¹ s⁻¹. Moreover, no significant variation in dose response was obseved when the gel samples are irridiated under different dose-rates as well as radiation beam energies. A noticeble change in the stability of the irradiated hydrogel samples was found within the first three days of irradiation, followed by a high post-irradiation stability, for the next 14 days. The non-irridiated samples were stable, up to 10 weeks.

Radon is a natural radioactive gas, which has great radiation hazards. Mastering the radon exhalation law under complex conditions is of great significance to the safety and stability of uranium tailings pond. Based on the self-developed artificial microclimate chamber, the single factor influence of water content, temperature and crack rate of overburden soil on radon exhalation rate of uranium tailings pond was explored through simulation experiments, and the corresponding single factor mathematical model was obtained. The response surface model of radon exhalation rate was constructed by combining whale optimization algorithm to achieve accurate prediction of radon exhalation rate. The test results of simulated seismic station vibration test also confirm the scientificity of the model. The results of this study can be used not only to guide the prediction and prevention of radon, but also to guide the early warning of uranium tailings pond instability.

Radioactive cesium rich microparticles (CsMPs) could partially increase ¹³⁷Cs concentration of the samples collected from the environment after the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the vertical distribution of CsMPs in soils collected from Fukushima Prefecture, Japan. The distribution of CsMPs was relatively large in the soil surface layer. However, the proportion of CsMPs in the RCs concentration at each soil depth was not large, less than 10%.

Spergularia rubra (L.) J. Presl & C. Presl has a mycorrhizal resistance that leads to increased uranium uptake. The results show that 35% of the ²³⁸U is retained in the carbonate fraction and 59% in the residual or non-reactive fraction. ²²⁶Ra shows a different pattern with an average association of 19% in the organic matter fraction, 10% in the carbonate compounds and the remaining 71% in the residual fraction. The relationships between the activity concentrations of ²³⁸U and ²²⁶Ra in the soil fractions and in Spergularia were found to be statistically representative of the carbonate and organic matter fractions, respectively.

The abandonment of stone quarries establishes a quarry lake ecosystem that includes soil, water, fish, and vegetarian cover. The activity concentrations (ACs) of natural radionuclides in the waters of several quarry lakes worldwide have not been investigated. In addition, the features of radionuclides, such as distribution, seasonal variability, and health risks, have not been studied. In this study, the ACs of ²²⁶Ra, ²³⁴U, and ²³⁸U were measured in a typical quarry lake in Vietnam with an area of approximately 4000 m². The average ACs of ²²⁶Ra, ²³⁴U, and ²³⁸U were 8.3, 13.8, and 17.7 mBq L⁻¹, respectively. The ratios of ²²⁶Ra/²³⁴U, ²²⁶Ra/²³⁸U, and ²³⁴U/²³⁸U were 0.47, 0.6, and 0.79, respectively. A linear correlation was found between ACs and water depth. The ACs predicted by the QWASI (Quantitative Water, Air, Sediment Interaction) model agree with the measured values.

Thermal properties of thorium nuclear fuels are influenced by the shape and size distribution of thorium oxide particles. The production of thorium oxide is significantly influenced by the size and shape of the thorium oxalate particles which are typically formed during precipitation process. This study investigated the synthesis of these particles in a micro-reactor system. In summary, the findings showed that at high concentrations of oxalic acid, increasing the total flow rate to a certain extent leads to a decrease in the size of the particles. Also, it was found increasing the reaction temperature leads to larger particles.