• Title, Summary, Keyword: Stable Isotope

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Lattice Design and Beam Dynamics Simulation for the Simultaneous Operation of Stable Ion Beam and Rare Isotope Beam in the RAON Accelerator

  • Jin, Hyunchang;Jeon, Dong-O
    • Journal of the Korean Physical Society
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    • v.71 no.11
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    • pp.824-830
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    • 2017
  • The Rare Isotope Accelerator of Newness (RAON) accelerator is under construction to generate and accelerate the stable ion beams and the rare isotope beams for various kinds of experiment programs. Especially, the post accelerator section was designed to be able to separately accelerate and transport the stable ion beams created by the superconducting electron cyclotron resonance ion source (ECR-IS) and the rare isotope beams created by the Isotope Separation On-Line (ISOL) system. However, recently, the research of the simultaneous operation of the stable ion beams and the rare isotope beams has been conducted to more efficiently satisfy the a wide range of beam requirements of the experimental halls. For the operation, we has modified the lattice of the post low energy beam transport (LEBT) section for the injection of the rare isotope beam and the next lattice after the low energy superconducting linac (SCL3) section for the extraction of the accelerated beam in the post accelerator section of the RAON accelerator. In this paper, the new lattice designs of the injection and extraction parts will be presented and we will describe the results of the beam dynamics simulations for the simultaneous operation of the two kinds of beams.

Applications and Prospects of Stable Isotope in Aquatic Ecology and Environmental Study (수생태 환경 연구에 있어 안정동위원소의 활용과 전망)

  • Choi, Bohyung;Shin, Kyung-Hoon
    • Korean Journal of Ecology and Environment
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    • v.51 no.1
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    • pp.96-104
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    • 2018
  • Stable isotope approach for aquatic ecology and environmental sciences has been introduced as very useful technique since 1980s and also has been applied to investigate various issues in aquatic ecology and environmental study last 10 years in Korea. Especially carbon and nitrogen isotope ratios have been mainly used to understand food web energy flow and ecosystem structure. In addition, nitrogen isotope ratio has been applied for nitrogen cycle and source identification as well as biomagnification studies. However, large temporal or spatial variations of nitrogen isotope ratio of primary producer have been found in many aquatic environments, and it is regarded as the critical problems to determine trophic level of aquatic animals. Recently, the compound specific isotope analysis of nitrogen within individual amino acids has been developed as an alternative method for trophic ecology. This article introduces the progress history of stable isotope application in aquatic ecology and environmental sciences, and also suggests new direction based on future prospects in stable isotope ecology and environmental study.

Application of Stable Isotope Ratio Analysis for Origin Authentication of Pork

  • Kim, Kyong Su;Kim, Jae Sung;Hwang, In Min;Jeong, In Seon;Khan, Naeem;Lee, Sun Im;Jeon, Dong Bok;Song, Yang Hoon;Kim, Kwan Suk
    • Food Science of Animal Resources
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    • v.33 no.1
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    • pp.39-44
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    • 2013
  • Origin authenticity of the animals used as food has always been a major concern to consumers around the world. In the past twenty years, a stable isotope ratio has been used for origin authentication. In this study, pork samples, both local and imported, were collected from the major markets from all around South Korea and analyzed for stable isotope ratios of nitrogen (${\delta}^{15}N$‰) and carbon (${\delta}^{13}C$‰), using Isotope Ratio Mass Spectrometry (IR-MS). A total of 599 samples with 335 Korean and 264 imported from 13 countries within America and Europe were investigated in accordance to the standard established methods for isotope ratio analysis. The results showed a significant variation related to the origin of the samples, explaining the difference in the feeding styles of the pork in each country. The stable isotope ratio values of carbon (${\delta}^{13}C$‰) were found in the decreasing order of: America ($-15.55{\pm}1.01$‰)>Korea ($-19.62{\pm}0.89$‰)>Europe ($-24.79{\pm}1.35$‰). Canada was having ${\delta}^{13}C$ ratio of $-22.87{\pm}0.92$‰, which is very low in the region of America and very close to Europe (-23.78 to -27.17‰). For nitrogen ${\delta}^{15}N$‰ the order was: America ($4.92{\pm}0.71$‰)>Europe ($4.54{\pm}0.66$‰)>Korea ($3.69{\pm}0.54$‰), with a slight variation among countries in each region studied. From the results it was concluded that the stable isotope ratio of the pork samples from different countries provide enough information about the origin and is therefore a potential tool which can be employed for origin authentication.

Stable C and N Isotopes: A Tool to Interpret Interacting Environmental Stresses on Soil and Plant

  • Yun, Seok-In;Ro, Hee-Myong
    • Journal of Applied Biological Chemistry
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    • v.51 no.6
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    • pp.262-271
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    • 2008
  • Natural abundances of stable isotopes of nitrogen and carbon (${\delta}^{15}N$ and ${\delta}^{13}C$) are being widely used to study N and C cycle processes in plant and soil systems. Variations in ${\delta}^{15}N$ of the soil and the plant reflect the potentially variable isotope signature of the external N sources and the isotope fractionation during the N cycle process. $N_2$ fixation and N fertilizer supply the nitrogen, whose ${\delta}^{15}N$ is close to 0%o, whereas the compost as. an organic input generally provides the nitrogen enriched in $^{15}N$ compared to the atmospheric $N_2$. The isotope fractionation during the N cycle process decreases the ${\delta}^{15}N$ of the substrate and increases the ${\delta}^{15}N$ of the product. N transformations such as N mineralization, nitrification, denitrification, assimilation, and the $NH_3$ volatilization have a specific isotope fractionation factor (${\alpha}$) for each N process. Variation in the ${\delta}^{13}C$ of plants reflects the photosynthetic type of plant, which affects the isotope fractionation during photosynthesis. The ${\delta}^{13}C$ of C3 plant is significantly lower than, whereas the ${\delta}^{13}C$ of C4 plant is similar to that of the atmospheric $CO_2$. Variation in the isotope fractionation of carbon and nitrogen can be observed under different environmental conditions. The effect of environmental factors on the stomatal conductance and the carboxylation rate affects the carbon isotope fractionation during photosynthesis. Changes in the environmental factors such as temperature and salt concentration affect the nitrogen isotope fractionation during the N cycle processes; however, the mechanism of variation in the nitrogen isotope fractionation has not been studied as much as that in the carbon isotope fractionation. Isotope fractionation factors of carbon and nitrogen could be the integrated factors for interpreting the effects of the environmental factors on plants and soils.

Effects of salmon carcass on forest and stream ecosystems, in Hokkaido, Japan -evidence by stable isotope analysis-

  • Yanai, Seiji;Kochi, Kaori
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • pp.198-203
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    • 2003
  • The effects of salmon carcasses on forest and stream ecosystems were determined by nitrogen stable isotope analysis in natural streams in Hokkaido, Northern Japan, where numerous chum salmon (Oncoryhncus keta) were migrated upstream ITom ocean to spawn in autumn. The leaves and soils surrounding riparian forest and stream dwelling invertebrates were collected before and after migration. The nitrogen stable isotope ratio $({\delta}^{15}N)$ of riparian vegetation (Salix spp.) were different depending on the presence of salmon and distance from the stream. The $({\delta}^{15}N)$ of stream dwelling invertebrates were different between salmon present and absent stream. This difference was tested using the experiment channel by implanting salmon carcasses. The nitrogen stable isotope ratio of epilithic algae and leaf shredding animals were nearly 3 higher in the salmon implanted treatment suggesting that around 20% of salmon derived nitrogen was uptake either in algae and leaf shredding invertebrates. These results suggest that the salmon carcasses effects not only on stream primary production but also on primary consumers, which decompose leaves fertilized with nitrogen from carcasses.

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Carbon Stable Isotope Ratios of Phytoplankton and Benthic Diatoms in Lake Katanuma with Reference to Those of Other Lakes

  • Kikuchi, Eisuke;Takagi, Shigeto;Shikano, Shuichi;Hideyuki, Doi
    • Korean Journal of Ecology and Environment
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    • v.38 no.spc
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    • pp.8-11
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    • 2005
  • Carbon stable isotope ratios of producers varied in lake ecosystems. In tile present study, we tried to estimate the seasonal variations of carbon isotope ratios of phytoplankton and benthic diatoms in a strongly acidic lake ecosystem. Lake Katanuma is a volcanic, strongly acidic lake (average pH of 2.2), located in Miyagi, Japan. Only two algal species dominate in Lake Katanuma; Pinnularia acidojaponica as a benthic diatom, and Chlamydomonas acidophila as a green alga. Carbon isotope values of P. acidojaponica varied seasonally, while those of particulate organic matter, which were mainly composed of C. acidophila remained fairly stable. The differences suggested that $CO_2$ gas was more frequently limited for P. acidojaponica than C. acidophila, since high density patches of benthic diatoms were sometimes observed on the lake sediment. Generally, carbon concentration mechanisms (CCMs)of microalgae can fix bicarbonate in lakes, and affect the carbon isotope values of microalgae. While, in Lake Katanuma, CCMs of the microalgae may scarcely function because of high $CO_2$ gas concentration and low pH. This is the reason for low seasonal amplitude of carbon isotope values of phytoplankton relative to those in other lakes.

Ginseng authenticity testing by measuring carbon, nitrogen, and sulfur stable isotope compositions that differ based on cultivation land and organic fertilizer type

  • Chung, Ill-Min;Lee, Taek-Jun;Oh, Yong-Taek;Ghimire, Bimal Kumar;Jang, In-Bae;Kim, Seung-Hyun
    • Journal of Ginseng Research
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    • v.41 no.2
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    • pp.195-200
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    • 2017
  • Background: The natural ratios of carbon (C), nitrogen (N), and sulfur (S) stable isotopes can be varied in some specific living organisms owing to various isotopic fractionation processes in nature. Therefore, the analysis of C, N, and S stable isotope ratios in ginseng can provide a feasible method for determining ginseng authenticity depending on the cultivation land and type of fertilizer. Methods: C, N, and S stable isotope composition in 6-yr-old ginseng roots (Jagyeongjong variety) was measured by isotope ratio mass spectrometry. Results: The type of cultivation land and organic fertilizers affected the C, N, and S stable isotope ratio in ginseng (p < 0.05). The ${\delta}^{15}N_{AIR}$ and ${\delta}^{34}S_{VCDT}$ values in ginseng roots more significantly discriminated the cultivation land and type of organic fertilizers in ginseng cultivation than the ${\delta}^{13}C_{VPDB}$ value. The combination of ${\delta}^{13}C_{VPDB}$, ${\delta}^{15}N_{AIR}$, or ${\delta}^{34}S_{VCDT}$ in ginseng, except the combination ${\delta}^{13}C_{VPDB}-^{34}S_{VCDT}$, showed a better discrimination depending on soil type or fertilizer type. Conclusion: This case study provides preliminary results about the variation of C, N, and S isotope composition in ginseng according to the cultivation soil type and organic fertilizer type. Hence, our findings are potentially applicable to evaluate ginseng authenticity depending on cultivation conditions.

Interpretation of the Origin of Water Pollutants by Oxygen (δ18O) and Nitrogen (δ15N) Isotope Analysis (산소(δ18O)와 질소(δ15N) 안정동위원소비를 이용한 상수원의 오염원 분석)

  • Jeong, Young-Cheol;Lee, Jeongyup;Choi, Jaewon;Kim, Yun S.
    • Journal of The Korea Society For Environmental Analysis
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    • v.20 no.1
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    • pp.20-29
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    • 2017
  • The use of chemical analyses for water quality management has limitations in terms of efficiently managing pollutants through various pollutants sources. For the purpose of identification, stable isotope ratio methods are wildly used around world. The measurement technique of oxygen and nitrogen stable isotopes in water is employed to establish the origin and pollution source in the water quality protection area in this study. The target study areas, which are a water resource, is located in G area, Korea, and the analytical samples were collected 4 times per year at 5 sites. As a result, the assigned values of oxygen and nitrogen stable isotopes in water were changed based on rainfall. The target area, water quality protection area, was estimated to be highly influenced by soil from land, manure and sewage, and contaminated groundwater. According to the correlation between oxygen and nitrogen stable isotope ratio, the study area is estimated to be influenced by pollution sources in D site, where inflow was not large.