scholarly journals Simulation Study for the Separation of Rare Isotopes at the Seoul National University AMS Facility

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 89-95 ◽  
Author(s):  
C C Yun ◽  
C S Lee ◽  
M Youn ◽  
J C Kim
Keyword(s):  
Simulation Study ◽  
Isotope Separation ◽  
Nuclear Astrophysics ◽  
Small Mass ◽  
Beam Line ◽  
Rare Isotope ◽  
Transport Code ◽  
National University ◽  
Rare Isotopes ◽  
Seoul National University

A simulation study for the separation of rare isotopes such as beryllium and aluminum was performed for a new beam line to be attached to the 3MV Tandetron accelerator at the accelerator mass spectrometry (AMS) facility of Seoul National University in Korea. The new beam line will also be used for other scientific applications, namely, ion implantations, Rutherford backscattering, and nuclear astrophysics experiments. It mainly consists of 30° and 100° deflection dipole magnets and drift spaces. A transfer matrix for the beam line was determined by the TRANSPORT code. Simulation of the rare isotope separation was performed by a ray tracing method using the TURTLE code. The simulation results, including the effect of the energy degrader, provide feasibility for the separation of isobars with small mass differences in 10Be-10B and 26Al-26Mg.

scholarly journals Nuclear theory and science of the facility for rare isotope beams

2014 ◽  
Vol 29 (11) ◽  
pp. 1430010 ◽  
Author(s):  
A. B. Balantekin ◽  
J. Carlson ◽  
D. J. Dean ◽  
G. M. Fuller ◽  
R. J. Furnstahl ◽  
...  
Keyword(s):  
Nuclear Structure ◽  
Critical Role ◽  
Nuclear Astrophysics ◽  
Current Theory ◽  
Comprehensive Description ◽  
Rare Isotope ◽  
Nuclear Theory ◽  
Nuclear Science ◽  
Traditional Fields ◽  
Rare Isotopes

The Facility for Rare Isotope Beams (FRIB) will be a world-leading laboratory for the study of nuclear structure, reactions and astrophysics. Experiments with intense beams of rare isotopes produced at FRIB will guide us toward a comprehensive description of nuclei, elucidate the origin of the elements in the cosmos, help provide an understanding of matter in neutron stars and establish the scientific foundation for innovative applications of nuclear science to society. FRIB will be essential for gaining access to key regions of the nuclear chart, where the measured nuclear properties will challenge established concepts, and highlight shortcomings and needed modifications to current theory. Conversely, nuclear theory will play a critical role in providing the intellectual framework for the science at FRIB, and will provide invaluable guidance to FRIB's experimental programs. This review overviews the broad scope of the FRIB theory effort, which reaches beyond the traditional fields of nuclear structure and reactions, and nuclear astrophysics, to explore exciting interdisciplinary boundaries with other areas.

scholarly journals Predictors of cervical myelopathy and hydrocephalus in young children with achondroplasia

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Youngbo Shim ◽  
Jung Min Ko ◽  
Tae-Joon Cho ◽  
Seung‐Ki Kim ◽  
Ji Hoon Phi
Keyword(s):  
Magnetic Resonance Imaging ◽  
Young Children ◽  
Cervical Myelopathy ◽  
Treatment Method ◽  
Foramen Magnum ◽  
Resonance Imaging ◽  
Timely Manner ◽  
Frontal Horn ◽  
National University ◽  
Seoul National University

Abstract Background Cervical myelopathy and hydrocephalus occasionally occur in young children with achondroplasia. However, these conditions are not evaluated in a timely manner in many cases. The current study presents significant predictors for cervical myelopathy and hydrocephalus in young children with achondroplasia. Methods A retrospective analysis of 65 patients with achondroplasia who visited Seoul National University Children’s Hospital since 2012 was performed. The patients were divided into groups according to the presence of cervical myelopathy and hydrocephalus, and differences in foramen magnum parameters and ventricular parameters by magnetic resonance imaging between groups were analyzed. Predictors for cervical myelopathy and hydrocephalus were analyzed, and the cut-off points for significant ones were calculated. Results The group with cervical myelopathy showed foramen magnum parameters that indicated significantly lower cord thickness than in the group without cervical myelopathy, and the group with hydrocephalus showed significantly higher ventricular parameters and ‘Posterior indentation’ grade than the group without hydrocephalus. ‘Cord constriction ratio’ (OR 5199.90, p = 0.001) for cervical myelopathy and ‘Frontal horn width’ (OR 1.14, p = 0.001) and ‘Posterior indentation’ grade (grade 1: OR 9.25, p = 0.06; grade 2: OR 18.50, p = 0.01) for hydrocephalus were significant predictors. The cut-off points for cervical myelopathy were ‘Cord constriction ratio’ of 0.25 and ‘FM AP’ of 8 mm (AUC 0.821 and 0.862, respectively) and ‘Frontal horn width’ of 50 mm and ‘Posterior indentation’ grade of 0 (AUC 0.788 and 0.758, respectively) for hydrocephalus. Conclusion ‘Cord constriction ratio’ for cervical myelopathy and ‘Frontal horn width’ and ‘Posterior indentation’ grade for hydrocephalus were significant predictors and may be used as useful parameters for management. ‘Posterior indentation’ grade may also be used to determine the treatment method for hydrocephalus.

scholarly journals Components of Metabolic Syndrome in Korean Adults: A Hospital-Based Cohort at Seoul National University Bundang Hospital

2019 ◽  
Vol 28 (2) ◽  
pp. 118-128 ◽  
Author(s):  
Soo Lim ◽  
Se Hee Min ◽  
Ji Hyun Lee ◽  
Lee Kyung Kim ◽  
Dong-Hwa Lee ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Korean Adults ◽  
National University ◽  
Seoul National University

Climate related variations in atmospheric nitrous oxide concentration during the Mid- to Late Holocene

2021 ◽  
Author(s):  
Syed Azharuddin ◽  
Jinho Ahn ◽  
Yeongjun Ryu ◽  
Ed Brook
Keyword(s):  
Nitrous Oxide ◽  
Late Holocene ◽  
Ice Core ◽  
Progressive Increase ◽  
La Niña ◽  
La Nina ◽  
National University ◽  
Seoul National University ◽  
Sudden Decrease ◽  
Nitrous Oxide Concentration

<p>Nitrous oxide (N<sub>2</sub>O) is an important greenhouse gas with sources that respond to the biogeochemical processes on land and ocean. The major sources of atmospheric N<sub>2</sub>O are nitrification and denitrification occurring in terrestrial soils and the ocean. Here we present a new high-resolution atmospheric N<sub>2</sub>O record obtained from South Pole Ice (SPICE) core site covering the Mid- to Late Holocene (since ~5.5 ka). The N<sub>2</sub>O analysis was performed in a specialised wet extraction facility installed at Seoul National University that used small ice samples (<20 g) to yield a high precision (average standard deviation of ~1ppb) record. The new N<sub>2</sub>O data agree well with existing records on the millennial scale and reveal new details on the multi-centennial scale. Our results show a progressive increase in atmospheric N<sub>2</sub>O during 5.5 to 3.2 ka which correlates well with the increase of marine denitrification around the Arabian Sea (AS) and Peru-Chile Margin (PCM) as well as Indian monsoon precipitation around the same period. A local minimum in N<sub>2</sub>O is observed around 2.8 ka, possibly related to a sudden decrease in Western Tropical South (WTS) Pacific sea surface temperature and increased La-Nina like conditions which may have supressed denitrification along PCM. These conditions may have further influenced the monsoons and reduced denitrification in land soils. Our record also shows a local N<sub>2</sub>O maximum around 2.2 ka which may correspond to relaxed La-Nina like conditions around WTS Pacific. Subsequently, the N<sub>2</sub>O further dropped to attain a pronounced minimum around 1.4 ka. Similar N<sub>2</sub>O minima are also observed in Styx (Antarctica) and  NEEM (Greenland) ice core records, demonstrating the robustness of the signals.</p>

scholarly journals Screening for early detection of lung cancer: results from Seoul National University Hospital.

1991 ◽  
Vol 38 (2) ◽  
pp. 119-127
Author(s):  
Yong Chol Han ◽  
Chul Gyu Yoo ◽  
Young Whan Kim ◽  
Sung Koo Han ◽  
Young Soo Shim ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Early Detection ◽  
University Hospital ◽  
National University ◽  
Seoul National University
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