• 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 the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4696-4703
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• 2011

Tetraazamacrocyclic ion-exchangers, 1,4,8,11-tetraazacyclotetradecane bonded Merrifield peptide resin(TDM), 1,4,8,12-tetraazacyclopentadecane bonded Merrifield peptide resin(TPM) were prepared, and the ion-exchange capacity of these TDM and TPM were characterized. The distribution coefficients in various conc. of NH4Cl for magnesium with ion exchangers were determined by using the batch method. We found the isotope separation factors on new prepared tetraazamacrocyclic ion-exchangers bonded Merrifield peptide resin(TDM, TPM). The isotope separation of magnesium was determined by using of breakthrough method of column chromatography.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.3
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• pp.199-212
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• 2023

Diffusion is a powerful tool to understand geological processes recorded in terrestrial rocks as well as extraterrestrial materials. Since the diffusive exchange of elements or isotopes may have occurred differently in the solar nebula (high temperature and rapid cooling) and on the parent bodies (fluid-assisted thermal metamorphism at relatively low temperature), it is particularly important to model elemental or isotopic diffusion profiles within the mineral grains to better understand the evolution of the early solar system. A numerical model with the finite difference method for the fast grain boundary diffusion was established for the exchange of elements or isotopes between constituent minerals in a closed system. The fast grain boundary diffusion numerical model was applied to 1) ²⁶Mg variation in plagioclase of an amoeboid olivine aggregate (AOA) from a CH chondrite and 2) Fe-Mg interdiffusion between chondrules, AOA, and matrix minerals in a CO chondrite. Equilibrium isotopic fractionation and equilibrium partitioning were also included in the numerical model, based on the assumption that equilibrium can be reached at the interfaces of mineral crystals. The numerical model showed that diffusion profiles observed in chondrite samples likely resulted from the diffusive exchange of elements or isotopes between the constituent minerals. This study also showed that the closure temperature is determined not only by the mineral with the slowest diffusivity in the system, but also strongly depends on the constituent mineral abundances.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.89-115
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• 1968

1. The experiment was carried out for investigating the interaction between potassium nutrition and thermoperiod (as an environment regulating factor) in relation to behaviors of several nutrients including phosphorus-32 and Potassium-42 in IPOMOEA BATAS. 2. To obtain same condition to trace the behaviors of phosphorus and potassum-42 they were simultaneously incorporated to roots. The determination of each CPM by counting twice with adequate interval and calculating true CPM of each isotope according to different half-life, was carried out with satisfactory. 3. Some specific symptoms i.e, chlorosis and withering of growing point under the condition of lower potassium level were found and was accelerated by the low night temperature. 4. A manganese shortage in growing point of the lower potassium level was found by activiation analysis and very low distribution ratio of phosphorus-32 and potassium-42 in the growing point of the lower potassium level was manifested, though the contents of nitrogen, phosphorus, potassium, sodium and magnesium were not in great difference. 5. In addition to the low water content with appearence of "hard", shorterning internode and lower ratio of roots to shoot as well as the symptoms of potassium deficiency such as brown spot in leaf blade and necrosis of leaf margin were appeared at later stage of experiment at the lower potassium level. 6. Very stimulating vegetative growth, e.g, large plant length, leaf expansion, increasing node number and fresh weight as well as high ratio of roots to shoot, high water content was resulted in the condition of higher potassium level. 7. A specific interaction between higher potassium level and thermoperiod was found, that is, the largest tuber production and the largest ratio of roots to shoot were resulted in the combined condition of higher potassium level and constant temperature while the largest plant length, fresh weight etc. i.e. the most stimulative vegetative growth was resulted in the combined condition of higher potassium level and low night temperature. 8. Comparatively low water content in the former condition of stimulative tuber production was resulted(especially at the tuber thickening stage), while high water content in the latter condition of stimulative vegetation was resulted though the higher potassium level made generally high water contents. 9. The nitrogen contents of soluble and insoluble did not make distinct difference between the lower and higher potassium level. 10. Though the phosphorus contents were not distinctly different by the potassium level, the lower potassium level made the percentage of phosphorus increased at tuber forming stage accumulating more phosphorus in roots, while the higher potassium level decreased percentage of phosphorus at that stage. 11. The higher potassium level made distinctly high potassium contents than the lower potassium level and increased contents at the tuber forming stage through both conditions. 12. The sodium contents were low in the condition of higher potassium level than the lower potassium level and decreased at tuber forming stage in both conditions, on the contary of potassium. 13. Except the noticeable deficeney of manganese in the growing point of the lower potassium level, mangense and magnesium contents in other organs did not make distinct difference according to the potassium level. 14. Generally more uptake and large absorption rate of phosphorus-32 and potassium-42 were resulted at the higher potassium level, and the most uptake, and the largest absorption rate of phosphorus and potassium-42 (especially potassium-42 at tuber forming stage) were resulted in the condition of higher potassium level and constant temperature which made the highest tuber production. 15. The higher potassium level stimulated the translocation of phoshorus-32 and potassium-42 from roots to shoots while the lower potassium level suppressed or blocked the translocation. 16. Therefore, very large distribution rate of $p^{32}$, $K^{42}$ in shoot, especially, in growing point, compared with roots was resulted in the higher potassium level. 17. The lower potassium level suppressed the translocation of phosporus-32 from roots to shoot more than that of potassium-42. 18. The uptake of potassium-42 and translocation in IPOMOEA BATATAS were more vivid than phosphorus-32. 19. A specific interaction between potassium nutrition and thermoperiod which resulted the largest tuber production etc. was discussed in relation to behaviors of minerals and potasium-42 etc. 20. Also, the specific effect of the lower and higher potassium level on the growth pattern of IPOMOEA BATATAS were discussed in relation to behaviors of minerals and isotopes. 21. An emphasize on the significance of the higher potassium level as well as the interaction with the regulating factor and problem of potassium level (gradient) for crops product ion were discussed from the point of dynamical and variable function of potassium.