• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.34-40
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• 2015

Studies using stable water vapor isotopes have been recently conducted over the past two decades because of difficulties in analysis and sample collection in the past. Stable water vapor isotope data provide information of the moisture transport from ocean to continent, which are also used to validate an isotope enabled general circulation model for paleoclimate reconstructions. The isotopic compositions of groundwater and water vapor also provide a clue to how moisture moves from soil to atmosphere by evapotranspiration. International Atomic Energy Agency designates the stations over the world to observe the water vapor isotopes. To analyze the water vapor isotopes, a cryogenic sampling method has been used over the past two decades. Recently, two types of laser-based spectroscopy have been developed and remotely sensed data from satellites have the global coverage. In this review, measurements of isotopic compositions of water vapor will be introduced and some studies using the water vapor isotopes will also be introduced. Finally, we will suggest the future study in Korea.

• Analytical Science and Technology
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• v.23 no.6
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• pp.518-523
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• 2010

In this paper, the study of analysis of uranium isotopes in environmental samples with a kinetic phosphorescence analyzer (KPA) was described. After leaching uranium fraction from soil and glass material with microwave acid digestion technology, uranium isotopes were purified with UTEVA column, and then measured using KPA. Linearity and repeatability tests for measurement of uranium isotopes were carried out in the uranium standard solution with KPA. The reliability for analytical method of uranium with KPA was validated by its application to uranium standard solution, ground water, IAEA and NIST reference samples.

• Journal of the Korean Chemical Society
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• v.21 no.2
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• pp.75-82
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• 1977

The isotope effect of pure liquid on vapor pressure is examined, and the vapor pressure ratios of two different isotopes are calculated. Based on the Significant Structure Theory of Liquids, the effect of molecular weight and the effect of moments of inertia are dominant in ordinary/trans-$d_2$ ethylene isotopes; the effect of hindered rotational zero-point energy is dominant in trans-$d_2$/cis-$d_2$ ethylene isotopes; and the effect of intermolecular potential difference is found in $CH_3OH/CH_3OD$ isotopes. In the isotopes of $CH_4/CD_4,\;SiH_4/SiD_4\;and\;GeH_4/GeD_4$, the weight effect decrease in the order of $CH_4/CD_4 >SiH_4/SiD_4 >GeH_4/GeD_4$.

• Journal of Radiation Protection and Research
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• v.26 no.1
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• pp.1-6
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• 2001

An accurate and rapid analytical technique of uranium isotopes in highly contaminated soil samples was developed and validated by application to the IAEA-Reference samples. For overcoming the demerits of the TBP extraction method, sample materials were decomposited with $HNO_3$ and HF, and uranium isotopes were purified by an anion exchange resin and a TRU Spec resin. With the extraction chromatography method, the hindrance elements were completely removed from the uranium fraction. The chemical yields with the extraction chromatography method were more 10% higher than those with the TBP extraction method. The concentrations of uranium isotopes in soil samples using the extraction chromatography method were consistent with the reference values reported by the IAEA.

• Mass Spectrometry Letters
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• v.7 no.3
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• pp.64-68
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• 2016

Scanning electron microscopy combined with thermal ionization mass spectrometry (SEM-TIMS) was used to determine the precise isotope ratios of ultra-trace levels of uranium contained in individual microparticles. An advanced multiple ion counter system consisting of three secondary ion multipliers and two compact discrete dynodes was used for complete simultaneous ion detection. For verification purposes, using TIMS with complete simultaneous measurement, isotopes were analyzed in 5 pg of uranium of a certified reference material. A microprobe in the SEM was used to transfer individual particles from a NUSIMEP-7 sample to TIMS filaments, which were then subjected to SEM-TIMS and complete simultaneous measurement. The excellent agreement in the resulting uranium isotope ratios with the certified NUSIMEP-7 values shows the validity of SEM-TIMS with complete simultaneous measurement for the analysis of uranium isotopes in individual particles. Further experimental study required for investigation of simultaneous measurement using the advanced multiple ion counter system is presented.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.159-164
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• 1963

The astatine isotopes produced in $He^3$ bombardment of bismuth were analysed with alpha ionization chamber and 100 channel pulse height analyser. The main product was $At^{209}$ formed by ($He^3$, 3n) reaction. Four other isotopes were also identified. Semi-quantitative calculation of relative yield of each isotope was attempted.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.237-237
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• 2003

Preliminary studies on the seasonal variations in abundance of stable isotopes were carried out on the snow and rainwater samples from urban area. Stable isotopes and other geochemical data as a tool for characterizing the seasonality and source of pollutants were examined in study areas, especially to trace the sources of sulfate in precipitation and to distinguish sulfates of natural and anthropogenic origin. (omitted)

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1255-1262
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• 2018

In this paper, alternative potentials to explain the scattering cross sections of $^{7,9,10,11,12,14}Be$ isotopes by a $^{12}C$ target nucleus at different energies are researched. For this purpose, fourteen different proximity potentials, such as Proximity 1966, Proximity 1976, Proximity 1977, Proximity 1979, Proximity 1984, Proximity 1988, Proximity 1995, Broglia and Winther 1991, Aage Winther, Bass 1973, Bass 1977, Bass 1980, Christensen and Winther 1976, and $Ng{\hat{o}}$ 1980, are used to produce the real potential within the optical model. The imaginary potential is formed by using the Woods-Saxon potential. The theoretical results are compared with both experimental data and data reported in the literature. The results are in good agreement with the data. The proximity potentials are observed to play a significant role in obtaining the scattering cross sections of $^{7,9,10,11,12,14}Be$ isotopes.

• Bulletin of the Korean Chemical Society
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• v.22 no.6
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• pp.570-574
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• 2001

Magnesium isotope separation was investigated by chemical ion exchange with the 1-aza-12-crown-4 bonded Merrifield peptide resin using an elution chromatographic technique. The capacity of the novel azacrown ion exchanger was 1.0 meq/g dry resin. The heavier isotopes of magnesium were enriched in the resin phase, while the lighter isotopes were enriched in the solution phase. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assys. The separation factors of $^{24}Mg^{2+}$-$^{25}Mg^{2+}$, $^{24}Mg^{2+}$-$^{26}Mg^{2+}$, and $^{25}Mg^{2+}$-$^{26}Mg^{2+}$ were 1.008, 1.019, and 1.006, respectively.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.22 no.2
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• pp.129-137
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• 2024

To non-destructively determine the burnup of a spent nuclear fuel assembly, it is essential to analyze the nuclear isotopes present in the assembly and detect the neutrons and gamma rays emitted from these isotopes. Specifically, gamma-ray measurement methods can utilize a single radiation measurement value of ¹³⁷Cs or measure based on the energy peak ratio of Cs isotopes such as ¹³⁴Cs/¹³⁷Cs and ¹⁵⁴Eu/¹³⁷Cs. In this study, we validated the extent to which the results of gamma-ray measurements using cadmium zinc telluride (CZT) sensors based on ¹³⁷Cs could be accurately simulated by implementing identical conditions on MCNP. To simulate measurement scenarios using a lead collimator, we propose equations that represent radiation behavior that reaches the detector by assuming "Direct hit" and "Penetration with attenuation" situations. The results obtained from MCNP confirmed an increase in measurement efficiency by 0.47 times when using the CZT detector, demonstrating the efficacy of the measurement system.