Journal of Radioanalytical and Nuclear Chemistry最新文献

Spatio-temporal isotopic variations and the driving forces in precipitation were explored in Eurasian continent. The results showed that δ¹⁸O, d-excess and δ²H-δ¹⁸O regressions all presented pronounced spatial heterogeneities among different climate zones, with the distance to sea and the latitude identified as main geographic controls. The Mann-Kendall test revealed that significant temperature increases were observed at the majority (18/20) of the sites. However, δ¹⁸O did not universally exhibit the same upward trend (5/20 sites) as temperature although significant positive δ¹⁸O-temperature correlations existed at most (18/20) sites. The combined effects of multiple environmental factors complicated the interpretation of isotopic signals.

Metal–organic frameworks (MOF) have been vigorously investigated as hybrid materials in recent decades due to their exceptional structural versatility and applications in diverse fields. The development of novel MOFs for radiation detection and luminescence-based dosimetry is the latest topic of interest. In this contribution, we have synthesized and characterized a Uranyl MOF, which shows an optically stimulated luminescence (OSL) phenomenon induced by ionizing radiation. OSL dosimetric studies were carried out on Uranyl MOF, which revealed that MOF has a linear dose–response up to 100 Gy with a 1.1 Gy minimum detection dose. It also shows good reusability, around 30% fading in one day, very low fading beyond one day to 30 days, and decent radiation stability (stable up to 10 kGy). Preliminary dosimetry results are promising and show that Uranyl MOF can be utilized in the field of low-dose radiation processing applications in the future.

The concentration of ²²²Rn, was measured in a house in Niška Banja town. The continuous radon monitor was used for measurements with standard uncertainty of 3%. The measurement of ambient dose equivalent rate, H*(10), was also performed, with standard uncertainty of 10%, using a dosimeter programmed for continuous radiation detection. The highest radon concentration was as much as being 7300 Bq/m³. A maximum value of H*(10) of 0.885 µSv/h was obtained. The variation of H*(10) almost linearly follows the changes in the concentration of ²²²Rn. The corresponding effective dose was as much as 74.30 mSv per year.

Hafnium oxide (HfO₂) exhibit chemical resistivity, thermal stability and mechanical resilience on account of which it is used in numerous applications in integrated and optical circuit technology. In the present work, HfO₂ thin films have been grown by atomic layer deposition (ALD) technique on silicon and glass substrate. After growth of the films were irradiated with the Xe ion beam with distinct fluence of 1E15–1E16 ions/cm². Optical properties of films were investigated by the UV–VIS and Photoluminescence (PL) spectroscopy. The crystallographic parameters were illustrated by X-ray diffraction (XRD) pattern of pristine and ion beam treated thin films. Morphology of surface has been studied through atomic force microscopy (AFM).

NAA is applied to a sample of 360 archaeological ceramics mostly dating to the Late Horizon (1470–1532 CE) from the major Inka center of Pachacamac and fourteen additional sites in the Lurín valley of Peru’s central coast. Results indicate Inka pottery was produced by multiple communities of practice working in distinct locations and the importation of small amounts of pottery from the Inka capital Cuzco, and networks of distribution for this pottery and sociopolitical boundaries in the region are discussed based on results.

Natural radioactivity was assessed in sediment samples collected along southern coastline of Tamil Nadu. Average activity concentrations of ²³⁸U, ²³²Th, and ⁴⁰K were determined (29 ± 3, 218 ± 6, and 80 ± 5 Bq kg^–1, respectively). Calculated parameters included radium equivalent activity (347 ± 12 Bq kg^–1), absorbed dose rate (273 ± 10 nGy h^–1), annual effective dose rate (0.33 ± 0.01 mSv y^–1), external hazard index (0.94 ± 0.03), annual gonadal dose equivalent (1026 ± 35 mSv y^–1), and excess lifetime cancer risk (1.17 ± 0.03). Multivariate statistical analyses were employed to examine correlations among the radioactive variables. The presence of heavy minerals in the samples was confirmed using X-ray diffraction.

Due to the rapid development of fusion energy, the treatment of tritium-containing organic waste liquid has attracted significant attention. In this work, with plant fiber as an additive, the grpahene-plant fiber hybrid aerogel (G/P-A) was fabricated and used to adsorb tritiated pump oil. Results show that, compared to pure graphene aerogel (G-A), G/P-A displays better equal volume adsorption capacity (Q_v) and higher adsorption efficiency. For pump oil, the maximum adsorption capacity was 49.39 mg/mg, and Q_v reached an impressive 663.2 mg/mL, which is 17.82% higher than G-A (562.9 mg/mL). For other different adsorption targets, the maximum adsorption capacity ranged from 38.9 to 52.1 mg/mg is obtained. Due to its cost-effectiveness, strong oil absorption capability, and resistance to radiation, G/P-A could be a promising candidate for the adsorption treatment of tritium-containing organic waste liquid, such as tritiated pump oil.

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In this study, we have labeled methacetin with carbon-11 [¹¹C] as a PET imaging radiotracer. The radiolabeling was carried out by reacting acetaminophen with [¹¹C]methyl iodide in the presence of a base using [¹¹C]methyl iodide. [¹¹C]methacetin was synthesized via methylation at 70 °C for 5 min with a radiochemical purity of 99.3 ± 0.4 % and radiochemical yield was 34.6 ± 4.7 %. The tissue distribution showed higher uptake in blood pool at 5 min followed by increased uptake in lungs, liver and spleen.

The uranium in the radioactive wastewater produced by uranium conversion process is higher than the emission limit value, so it is of great significance to treat it to reduce its concentration. Nanofiltration technology and ion exchange technology were combined to treat uranium-containing wastewater and it can achieve the discharge standard. For the treatment system, uranium was firstly enriched in nanofiltration concentrate, and the concentrate entered the ion exchange system for selective adsorption of uranium. Because uranium exists in the form of complex cations or anions at different pH conditions, the use of cation–anion exchange resin tandem treatment technology can effectively and selectively adsorb almost all uranium. Both laboratory and engineering application results showed that the uranium concentration in the nanofiltration solution can be reduced to less than 50 μg/L after treating by the nanofiltration system for the wastewater containing 5–100 mg/L uranium. This work demonstrated that nanofiltration-ion exchange technology is practical and valuable for the treatment of acidic or alkaline uranium-containing waste liquid.

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