• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.107-113
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• 2009

In this study, the importance of failure analysis on large ring forged products was assessed and the process and methodology were introduced. Failure analysis case study of the large ring forged steel product with approximately 10 mm long internal crack found by non-destructive test (NDT) was presented. The micrographic and fractographic observations and the verifying tests were conducted on the cracked specimen to identify the possible metallurgical reason for the defects, and the metallurgical aspects of internal crack formation were discussed.

• 대한화학회지
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• 제13권3호
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• pp.229-232
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• 1969

2,2-gem-dephenylaziridine의 醋酸에 의한 開環反應에서 反應生成物은1,1-diphenyl-2-amino-ethyl acetate 임을 알았다. 또한 이 開環反應은 aziridine環 안에 있는 窒素原子와 tertiary炭素原子사이의 結合이 切斷되어 中間體로서 carbonium이온이 形成되는 過程을 거쳐서 進行됨을 알았다.

• Journal of Microbiology and Biotechnology
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• 제23권10호
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• pp.1347-1356
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• 2013

Tricholoma matsutake, an ectomycorrhiza that has mutual relationships with the rootlet of Pinus denisflora, forms a fruiting body that serves as a valuable food in Asia. However, the artificial culture of this fungus has not been successful. Soil fungi, including T. matsutake, coexist with many other microorganisms and plants; therefore, complex microbial communities have an influence on the fruiting body formation of T. matsutake. Here, we report on the structures of fungal communities associated with the fairy ring of T. matsutake through the pyrosequencing method. Soil samples were collected inside the fairy ring zone, in the fairy ring zone, and outside the fairy ring zone. A total of 37,125 sequencing reads were obtained and 728 to 1,962 operational taxonomic units (OTUs) were observed in the sampling zones. The fairy ring zone had the lowest OTUs and the lowest fungal diversity of all sampling zones. The number of OTUs and fungal taxa inside and outside the fairy ring zone was, respectively, about 2 times and 1.5 times higher than the fairy ring. Taxonomic analysis showed that each sampling zone has different fungal communities. In particular, out of 209 genera total, 6 genera in the fairy ring zone, such as Hemimycena, were uniquely present and 31 genera, such as Mycena, Boletopsis, and Repetophragma, were specifically absent. The results of metagenomic analysis based on the pyrosequencing indicate a decrease of fungal communities in the fairy ring zone and changes of fungal communities depending on the fairy ring growth of T. matsutake.

• 천문학회보
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• 제41권1호
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• pp.33.2-33.2
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• 2016

Since the serendipitous discovery of a large-scale atomic hydrogen ($H_I$) ring discovered in the Leo I galaxy group, its origin has been under debate till today, whether it is the leftover after group formation or stripped gas structure during the galaxy-galaxy interaction. Intriguingly a number of $H_I$ clumps have been identified along the gas ring, some of which turn out to be associated with optically catalogued dwarf galaxies. The formation history based on detailed optical and $H_I$ gas properties of those dwarf galaxies will enable us to verify the origin of the Leo ring. In this work, we first probe the redshift and multi-color properties of those dwarf galaxies, using deep photometric and spectroscopic data from CFHT, Gemini and Magellan telescope.

• Clinical and Experimental Pediatrics
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• 제48권1호
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• pp.108-111
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• 2005

20 환 염색체는 경한 외관상 기형, 정신 지체, 행동 장애, 난치성 간질을 동반하는 드문 염색체 이상 증후군이다. 저자들은 본원 소아과에 언어 발달 지연과 성장 발육 부전을 주소로 내원한 18개월 된 환자에서 말초혈액 염색체 및 FISH 검사를 통해 20 환 염색체 증후군으로 판명하였고 특징적인 난치성 간질 발작을 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 소성∙가공
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• 제27권5호
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• pp.289-295
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• 2018

The profile ring rolling process can realize various ring shapes unlike conventional rectangular cross-sectional ring products. In this paper, the defective groove in the bottom surface of L-shaped ring products was analyzed. Grooves are generated by non-uniform external forces due to profile main roll and initial blank shape. Process parameters such as the motion of dies and working temperature were determined. Mechanism of groove formation was analyzed by FE simulation on the basis of local external forces acting on the blank. Analysis results were similar to the groove actually occurring in the production line. Based on results of the analysis, two solutions were proposed for the groove. The position of the base plate supporting the blank was adjusted and edge length of the main roll was extended to suppress growth of grooves. It has been verified that groove was improved by applying two proposed methods in the shop-floor.

• 천문학회보
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• 제36권2호
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• pp.113.1-113.1
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• 2011

The Leo ring in the M96 group is unique in its morphology and size among the intergalactic gas features found in nearby universe. Its ring-like structure of 200 kpc on diameter appears to be orbiting around the M105-NGC 3384 pair with $1.67{\times}109\;M{\odot}$ of HI gas. While the origin of the ring - whether it is primordial or tidally stripped - is yet unclear, the optical and gas properties of dwarf galaxies associated with the gas ring help us to understand the formation process of this large scale intergalactic HI cloud. At the first step, we present the optical catalog of dwarf galaxy candidates in the Leo ring using deep optical images with MegaCam on the CFHT. Image convolution method is used in order to detect very faint dwarf galaxies. Comparing the ALFALFA HI data from the literature, we have identified that 4 dwarf candidates coexist with HI clumps. There are also 27 HI dwarfs with no optical counterpart and 12 optical dwarfs with no HI clump. In this work, we probe the optical and global gas properties of these dwarfs.

• BMB Reports
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• 제35권6호
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• pp.629-636
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• 2002

Protein kinase CKII (CKII) is required for progression through the cell division cycle. We recently reported that the $\beta$ subunit of protein kinase CKII ($CKII{\beta}$) associates with CKBBP1 that contains the Ring-H2 finger motif in the yeast two-hybrid system. We demonstrate here that the Ring-H2 finger-disrupted mutant of CKBBP1 does not interact with purified $CKII{\beta}$ in vitro, which shows that the Ring-H2 finger motif is critical for direct interaction with $CKII{\beta}$. The CKII holoenzyme is efficiently co-precipitated with the wild-type CKBBP1, but not with the Ring-H2 finger-disrupted CKBBP1, from whole cell extracts when epitope-tagged CKBBP1 is transiently expressed in HeLa cells. Disruption of the Ring-H2 finger motif does not affect the cellular localization of CKBBP1 in HeLa cells. The increased expression of either the wild-type CKBBP1 or Ring-H2 finger-disrupted CKBBP1 does not modulate the protein or the activity levels of CKII in HeLa cells. However, the stable expression of Ring-H2 finger-disrupted CKBBP1 in HeLa cells suppresses cell proliferation and causes the accumulation of the G1/G0 peak of the cell cycle. The Ring-H2 finger motif is required for maximal CKBBP1 phosphorylation by CKII, suggesting that the stable binding of CKBBP1 to CKII is necessary for its efficient phosphorylation. Taken together, these results suggest that the complex formation of $CKII{\beta}$ with CKBBP1 and/or CKII-mediated CKBBP1 phosphorylation is important for the G1/S phase transition of the cell cycle.

• 한국결정학회지
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• 제11권4호
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• pp.200-206
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• 2000

In a 200 mm Cz-Si crystal, a macroscopic fluctuation in pulling rate was intentionally introduced then the variations of the pulling rate and the formation behaviors of grow-in defects were compared. The diameters of the OSF-ring and the FPD area were affected by the fluctuation in the region above 1100℃. The COP density depended on the diameter of the OSF-ring. ΔOi and BMD were affected by the fluctuation in the region near 1000Δ. As the result, when a macroscopic fluctuation in pulling rate is introduced, the quality of crystal in the region of 150 mm from the growth interface should be reviewed carefully because it can be affected by the fluctuation.

• Bulletin of the Korean Chemical Society
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• 제25권3호
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• pp.351-356
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• 2004

Selected MPEG-b-PDLLA block copolymers have been synthesized by ring-opening polymerization with systematic variation of the chain lengths of the resident hydrophilic and hydrophobic blocks. The size and shape of the micelles that spontaneously form in solution are then controlled by the characteristics of the block copolymer template. All the materials prepared in this study showed the tunable pore size of 20-80 ${\AA}$ with the increase of hydrophobic chain lengths and up to 660 $m^2$/g of specific surface area. The formation mechanism of these nanoporous structures obtained by controlling the micelle size has been confirmed using both liquid and solid state $^{13}C\;and\;^{29}Si$ NMR techniques. This work verifies the formation mechanism of nanoporous structures in which the pore size and wall thickness are closely dependent on the size of hydrophobic cores and hydrophilic shells of the block copolymer templates.