Yongheum Jo

) was measured by calorimetry at 25 °C. Based on thermodynamic data obtained in this work, the approximation models were examined for the prediction of the temperature effect on the complexation, and the constant enthalpy approximation with the chemical complexation reaction modified to an isoelectric reaction showed a satisfactory prediction of in the temperature range of 10-70 °C. Finally, the results of U(vi) speciation in groundwater indicated that the dominance of calcium uranyl tricarbonat

The ternary alkaline earth metal uranyl tricarbonate complexes, MnUO2(CO3)32n-4 (M = Mg and Ca), have been considered to be the major U(vi) species contributing to uranium mobility in natural water. Although MgUO2(CO3)32- can account for a substantial portion of U(vi) in a Mg2+-rich aqueous system and most processes regarding uranium are subjected to variable temperatures, chemical thermodynamic data for the prediction of the formation of MgUO2(CO3)32- at variable temperatures are still unknown.

We present the first experimental evidence for the ternary complexation of calcium and magnesium ions with plutonyl(vi)tricarbonate species in carbonate-containing aqueous solutions using visible-NIR spectrophotometric titration. Prior to studying the ternary plutonyl(vi) carbonate complexation, visible-NIR absorption spectral information of PuO2(CO3)22- and PuO2(CO3)34- was successfully obtained. PuO2(CO3)22- has a prominent peak at 853 nm and its molar absorptivity was determined to be ε853, P

This study introduces a novel optical system integrating laser ablation with saturated absorption spectroscopy (LA-SAS) for the detection of neodymium isotopes, crucial for the characterization process in nuclear forensics. Conventional methods for isotope analysis have encountered challenges, such as the inability to perform on-site detection or difficulty in distinguishing minor isotope differences. The LA-SAS system overcomes these limitations by combining pulsed laser for ablation and counte

Abstract This review provides an overview of the chemical thermodynamics on ternary earth-alkaline metal-actinyl-tricarbonate systems (i.e., M-AnO 2 -CO 3 , M = Mg, Ca, Sr, and Ba) and discusses the aqueous complexation and dissolution/precipitation equilibrium for these ternary aqueous systems. The aqueous ternary U(VI) carbonate species are remarkably predominant in the U(VI) speciation under natural environmental conditions at ambient temperature and moderate ionic strength condition, while t

The uptake of chloride (Cl−) and isosaccharinic acid (ISA, main degradation product of cellulose) by cement paste with high slag content (CEM III/C) was investigated with batch sorption experiments with 36Cl and inactive ISA. A weak uptake of chloride was quantified (0.43 ≤ Rd [L∙kg−1] ≤ 5.8), consistently with previous observations for Portland cement. C-S-H, AFm and hydrotalcite are suggested as primary sinks for Cl−. XRD confirmed the formation of Friedel's salt at [NaCl] ≥ 1 M, consistent wi