한국잔디 수집계통들 중에서 우수계통들의 생육특성 비교

임용우(Y. W. Rim),김기용(K. Y. Kim),김맹중(M. J. Kim),성병렬(B. R. Sung),임영철(Y. C. Lim),정의수(E. S. Chung),신홍균(H. K. Shin),김용선(Y. S. Kim) 한국잡초학회·한국잔디학회 2003 Weed & Turfgrass Science Vol.17 No.2,3

2001년 수집된 한국잔디 133계통들 중에서 우수한 계통들을 선발하기위하여 밀도(품질),<br/> 피복성, 녹색기간, 내병성, 출수유무(종자수) 등의 주요특성과 그 외 생육특성들이 조사되었다. 생육특성이 우수한 6계통이 선발되었으며 그 결과를 요약하면 다음과 같다.<br/> 수집된 133계통들 중에서 가장 녹색기간이긴 계통은 J01067으로 11월초까지 녹색도를 유지하였다. J01106 및 J01129 계통들은 엽폭이 각각 1.5mm 및 2mm 정도로 매우 좁으며, 밀도가 높고, 피복성도 좋은 것으로 나타났으며, 내병성도 강하였다. J01122 계통은 들잔디 계통들 중에서 유일하게 내병성이 강한 계통으로 선발되었다. J01128 계통은 엽폭이 3.2mm로 중엽에 속하였으며, 대비품종인 Sunburst 와 비슷하였다. 이 계통의 경우도J01106, J01129 계통들과 마찬가지로 밀도가 높고 내병성이 강한 것으로 나타났다.<br/> 수집된 133계통들의 형태적 분류를 위하여 5가지의 생육특성을 사용하여 크게 세가지 군집<br/> 으로 분류하였으며, 그 중에서 대비품종으로 사용된 6품종들과 선발된 우수 6계통의 분류는<br/> 다음과 같다. 제 1군집에 속하는 품종 및 계통은 Belare, Meyer, 안양중지(Anyang-jungji), J01067, J01112 등이 포함되었으며, 제 2군집으로는 S-94, J01105가 포함되었고, 제 3군집에는 Sunburst, 건희(Konhee), J01106, J01128, J01129 등이 포함되었다. Growth characteristics such as density(quality), covering speed, green period, disease resistance, heading existence(number of seeds) and other characteristics were examined for selection of superior lines among the 133 zoysiagrass lines collected in 2001. Six superior lines were selected and the results were summarized as follows.<br/> Superior line, J01067 was longest for green period among the 133 zoysiagrasses and stayed green until the beginning of November. Leaf width of J01106 and J01129 lines was very narrow as 1.5㎜ and 2㎜, respectively and superior for density(quality), covering speed and disease resistance. J01122 line was selected for strongest disease resistance among the lines of Zoysia japonica. Leaf width of J01128 was 3.2㎜ showing midium type and similar to standard cultivar, Sunburst. This line also showed higher density and strong disease resistance like J01106 and J01129.<br/> Five growth characteristics for morphological classification of 133 zoysiagrass lines<br/> was used and divided into 3 cluster groups. Of 133 lines, 6 standard cultivars and 6 superior lines were classified as follows. First cluster group contained Belare, Meyer, Anyang-jungji, J01067, J01122, and second group contained S-94 and J01105, and third group contained Sunburst, Konhee, J01106, J01128 and J01129.<br/> <br/>

Effect of boron addition on thermal and mechanical properties of Co-Cr-Mo-C-(B) glass-forming alloys

Kim, Jeong Tae,Hong, Sung Hwan,Bian, Xilei,Gokuldoss, Prashanth Konda,Song, Kaikai,Eckert, Jü,rgen,Park, Jin Man,Kim, Ki Buem Elsevier 2018 INTERMETALLICS Vol.99 No.-

<P><B>Abstract</B></P> <P>In this work, we investigated the effect of boron addition on glass-forming ability and mechanical properties of Co-Cr-Mo-C alloys. The starting alloy was (Co<SUB>0.65</SUB>Cr<SUB>0.13</SUB>Mo<SUB>0.22</SUB>)<SUB>80</SUB>C<SUB>20</SUB> derived from the Co<SUB>65</SUB>Cr<SUB>13</SUB>Mo<SUB>22</SUB> ternary eutectic composition. This alloy is almost fully crystalline and exhibits brittle mechanical properties. Replacing carbon with boron allows obtaining bulk metallic glasses (BMGs) and bulk metallic glass composites. The designed alloys show very high strength (∼4100 MPa), wide super-cooled liquid region (∼100 K) and large endothermic enthalpy of the supercooled liquid region (∼35 J/g), indicating high thermal stability. The electronegativity difference and supercooled liquid region of the present alloys are comparable to rare-earth elements containing BMGs. The physical properties of the present alloys corresponded well with the alloy design strategy based on the unified parameter using the glass transition temperature, fracture strength, and molar volume. Furthermore, we propose the optimum compositional condition for glass formation by controlling the carbon-to-boron ratio and the influence of carbon on phase formation in this alloy system is discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of boron/carbon ratio on the glass formation, fracture strength, and thermal stability of Co-Cr-Mo eutectic alloy. </LI> <LI> The wide supercooled liquid region of 100 K when carbon to boron ratio is 2:1. </LI> <LI> The excellent thermal stability of supercooled liquid can offer a wide enough processing window for thermoplastic forming. </LI> <LI> The electronegativity difference is an indicator dominating the extension of the supercooled liquid region. </LI> </UL> </P>

Quasi-Monoenergetic Electron-Beam Generation Using a Laser Accelerator for Ultra-Short X-ray Sources

J Kim,고도경,석희용,H Jang,김형택,I Hwang,최일우,J Lim,J. Lee,J. H. Sung,K.-H. Hong,허민섭,N Hafz,유승훈,유태준,T. M. Jeong,V Kulagin,Y.-C. Noh 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.I

Two types of electron acceleration methods have been conducted to generate quasi-monoenergetic electron beams. Multi-MeV quasi-monoenergetic high-charge electron beams were generated at Korea Electrotechnology Research Institute (KERI) from self-modulated laser wakefield acceleration by using a collimator with a 2 TW (1.4 J/700 fs) Nd:glass/Ti:sapphire hybrid laser system and a supersonic nitrogen gas jet. The peak electron energy was 3.6 MeV, and the energy spread was 4 MeV. These electron beams are useful for the generation of short-pulse X-rays in the water window region, which is 250 eV -- 500 eV (2.5 -- 5 nm), by using Thomson scattering. The calcualted photon spectrum indicates the scattered photon covers the water window region. This can be used for a high spatial and temperal resolution microscope for medical imaing. To generate higher-energy electron beams with small energy spread, a laser wakefield acceleration experiment with a sharp downward electron density gradient was conducted with a 100 TW laser system at Advanced Photon Research Insistitute (APRI). With the electron density gradient, some background plasma electrons could be locally injected in the laser wake wave and a small energy spread was expected. Using the pre-pulse, we could generate sharp downward electron density gradients. The gradient scale length was 20 $\mu$m for a 25 \% density change. With this electron density gradient, we could get more reproducible electron beams than we could without the density gradient.

Effect of oxygen partial pressure on the morphology and properties of Ce doped YBCO films fabricated by a MOCVD process

Kim, Y.H.,Kim, C.J.,Jun, B.H.,Sung, T.H.,Han, Y.H.,Han, S.C.,Paik, H.J.,Youn, J.S.,No, K. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15

Rare-earth (RE) (e.g. Sm, Dy, Ce, etc.) doping has been widely investigated to improve critical current density (J<SUB>c</SUB>) of YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-X</SUB> (YBCO) coated conductors (CC). Oxygen partial pressure is known to be a key parameter in terms of affecting the J<SUB>c</SUB> of YBCO films. In this work, the effect of oxygen partial pressure on the microstructure and J<SUB>c</SUB> of a Ce doped YBCO film was examined. Ce doped YBCO films were deposited on (100) SrTiO<SUB>3</SUB> (STO) single crystal substrates at oxygen partial pressures of 2.5, 5.0, and 10.0Torr using a metal organic chemical vapor deposition (MOCVD) method. Due to the enhanced migration of surface adatoms under reduced oxygen partial pressure, a 1wt% Ce doped YBCO film had a stoichiometric, dense surface. In addition, the zero-field J<SUB>c</SUB> (at 77K) of the 1wt% Ce doped YBCO film deposited at reduced oxygen partial pressure was increased. Irrespective of the amount of Ce, the Ce doped YBCO film showed an increased zero-field J<SUB>c</SUB> (at 77K) under reduced oxygen partial pressure.

Snail1 is Stabilized by O-GlcNAc Modification in Hyperglycemic Condition and Causes Epithelial-Mesenchymal Transition

Sang Yoon Park,Hyun Sil Kim,Nam Hee Kim,Suena Ji,So Young Cha,Jeong Gu Kang,Ichiro Ota,Keiji Shimada,Noboru Konishi,Hyung Wook Nam,Won Ho Yang,Jürgen Roth,Jong In Yook,Jin Won Cho 한국당과학회 2010 한국당과학회 학술대회 Vol.2010 No.1

Protein O-phosphorylation can occur reciprocal with O-GlcNAc modification and represents a regulatory principle for proteins. O-phosphorylation of serine by GSK-3β on Snail1, a transcriptional repressor of E-cadherin and a key regulator of the epithelial-mesenchymal transition (EMT) program, results in its proteasomal degradation. We show that Snail1 carries O-GlcNAc at serine112 that stabilizes it by suppressing O-phosphorylation-mediated degradation. Stabilization by O-GlcNAc of Snail1 results in attenuation of E-cadherin mRNA expression. Enhanced O-GlcNAc modification occurred under hyperglycemic conditions and initiated EMT by transcriptional suppression of E-cadherin through Snail1. Thus, a molecular link exists between cellular glucose metabolism and the control of EMT by dynamic reciprocal O-phosphorylation and O-GlcNAc modification of Snail1.

Four novel RUNX2 mutations including a splice donor site result in the cleidocranial dysplasia phenotype

Kim, Hyo-Jin,Nam, Soon-Hyeun,Kim, Hyun-Jung,Park, Hyo-Sang,Ryoo, Hyun-Mo,Kim, Shin-Yoon,Cho, Tae-Joon,Kim, Seung-Gon,Bae, Suk-Chul,Kim, In-San,Stein, Janet L.,van Wijnen, Andre J.,Stein, Gary S.,Lian, Liss 2006 Journal of Cellular Physiology Vol.207 No.1

<P>Cleidocranial dysplasia (CCD) is an autosomal dominant disorder caused by haploinsufficiency of the RUNX2 gene. In this study, we analyzed by direct sequencing RUNX2 mutations from eleven CCD patients. Four of seven mutations were novel: two nonsense mutations resulted in a translational stop at codon 50 (Q50X) and 112 (E112X); a missense mutation converted arginine to glycine at codon 131 (R131G); and an exon 1 splice donor site mutation (donor splice site GT/AT, IVS1 + 1G > A) at exon 1–intron junction resulted in the deletion of QA stretch contained in exon 1 of RUNX2. We focused on the functional analysis of the IVS1 + 1G > A mutation. A full-length cDNA of this mutation was cloned (RUNX2Δe1) and expressed in Chinese hamster ovary (CHO) and HeLa cells. Functional analysis of RUNX2Δe1 was performed with respect to protein stability, nuclear localization, DNA binding, and transactivation activity of a downstream RUNX2 target gene. Protein stability of RUNX2Δe1 is similar to wild-type RUNX2 as determined by Western blot analysis. Subcellular localization of RUNX2Δe1, assessed by in situ immunofluorescent staining, was observed with partial retention in both the nucleus and cytoplasm. This finding is in contrast to RUNX2 wild-type, which is detected exclusively in the nucleus. DNA binding activity was also compromised by the RUNX2Δe1 in gel shift assay. Finally, RUNX2Δe1 blocked transactivation of the osteocalcin gene determined by transient transfection assay. Our findings demonstrate for the first time that the CCD phenotype can be caused by a splice site mutation, which results in the deletion of N-terminus amino acids containing the QA stretch in RUNX2 that contains a previously unidentified second nuclear localization signal (NLS). We postulate that the QA sequence unique to RUNX2 contributes to a competent structure of RUNX2 that is required for nuclear localization, DNA binding, and transactivation function. J. Cell. Physiol. 207: 114–122, 2006. © 2005 Wiley-Liss, Inc.</P>

Martingale 에 대한 중심극한정리

주상렬(Sang-Yeorl J00),김정일(Jung-IL Kim),김윤경(Yun-Kyong Kim) 강원대학교 기초과학연구소 1985 기초과학연구 Vol.2 No.-

1937년, P.Levy에 의하여 Lindeberg의 중심극한정리가 martingale인 경우로 확장된 이래 martingale극한론에 대하여 많은 연구가 진행되어왔다. 이 논문에서는 L²-martingale array {S??,F??,l≤j≥k??}에 대하여 {S??}이 표준정규분포에 분포수렴하기 위한 충분조건을 다루었다. Since,P.Levy showed that Lindeberg's central limit theorem could be extended to martingales in 1937, the martingale limit theory have been studied by many Mathematicians. In this paper, for a square-integrable martingale array {S??,F??,l≤j≤k??} we give sufficient conditions for which {S??} converges in distribution to the standard normal random variable.

열선 화학 기상 증착법에 의한 실리콘 박막 및 태양전지 특성

김상균(Kim, Sang-Kyun),이정철(Lee, Jeong Chul),전상원(Jeon, Sang Won),임충현(Lim, Chung Hyun),안세진(Ahn, Sae Jin),윤재호(Yun, Jae Ho),김석기(Kim, Seok Ki),송진수(Song, Jinsoo),박성주(Park, S-J),윤경훈(Yoon, Kyung Hoon) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

최근 열선 화학 기상 증착법(HWCVD)은 낮은 온도에서 TFT용 Poly Si 중착을 할 수 있다는 점과 실리콘 박막을 빠른 속도로 증착할 수 있다는 점에서 각광을 받고 있다. 본 연구에서는 HWCVD를 이용하여 태양전지를 제조하고 그 특성을 평가하였다. 조건에 따른 실리콘 박막의 특성 변화를 알기 위해 corning glass 및 실리콘 wafer에 다양한 조건에서 단위 박막(intrinsic layer)을 증착하였고 이 결과를 바탕으로 p/i/n 구조의 태양전지를 제조하였다. Ta 열선 온도는 1700-2000도였고 가스 원료인 SiH₄와 수소의 비율을 조절하면서 그 영향을 관찰하였다. 태양전지의 경우 p충과 n충은 PECVD로 증착하였으며 단위박막 및 태양전지 i충 증착시 기판과 열선간의 거리는 7cm, 기판 온도는 200?C와 250?C로 고정하였고 작업압력은 30mTorr였다. 단위 박막 특성 평가를 위해 암/광 전도도, SEM, Raman Scattering, FT-IR등을 사용하였으며 태양전지 특성 평가를 위해 I-V 및 Spectral response를 측정하였다. 열선 온도가 증가함에 따라 증착속도 및 결정화 분율은 증가하였다. 특히 비정질에서 결정질로 전이되는 구간은 매우 좁았으며 여러 분석 방법에서 일치되는 결과를 보였다. SiH₄ 유량이 늘어날수록 비정질이 결정질로 바뀌는 열선 온도가 증가하였으며 기판 온도가 낮을 경우 또한 결정으로 바뀌는 열선 온도가 증가하였다. 태양전지의 경우 열선 온도가 증가함에 따라 V_{oc} 및 W가 낮아졌으며 J_{sc}, 는 증가하는 경향을 보였으며 결정질 비율이 증가하는 것을 관찰할 수 있었다. 이러한 경향은 quantum efficiency 결과에서도 확인할 수 있었다.

Particle distribution in melt-processed Y_1.5 Ba₂Cu₃O_x superconductors with BaCeO₃ addition

Youn, J.S.,No, K.,Kim, Y.H.,Mahmood, A.,Jun, B.H.,Han, Y.H.,Sung, T.H.,Kim, C.J. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15

To understand the effect of BaCeO<SUB>3</SUB> on a Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) distribution, Y<SUB>1.5</SUB>Ba<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>x</SUB> (Y1.5) superconductors with/without 1wt.% BaCeO<SUB>3</SUB> additions were prepared by a top-seeded melt-textured growth (TSMG) process. Two different BaCeO<SUB>3</SUB> powders (as-synthesized (coarse powder) and an attrition-milled (fine powder)) were used and the size effect was compared with that obtained from a Y1.5 sample with no addition. A refinement of the Y211 particles was achieved for both the as-synthesized and attrition-milled BaCeO<SUB>3</SUB> additions. The distribution of the Y211 particles was most uniform in the Y1.5 sample prepared with the attrition-milled BaCeO<SUB>3</SUB> powder due to the reduced size of the Y211-free regions by the fine size BaCeO<SUB>3</SUB> addition. The highest J<SUB>c</SUB> was achieved in the Y1.5 sample prepared with the attrition-milled BaCeO<SUB>3</SUB> powder. The J<SUB>c</SUB> result agreed well with the microstructure variations by the addition of BaCeO<SUB>3</SUB> powders.

복합산화물이 형성된 API X80 라인파이프강의 용접열영향부 샤르피 흡수에너지

성효경 ( Hyo Kyung Sung ),신상용 ( Sang Yong Shin ),차우열 ( Woo Yeol Cha ),오경식 ( Kyung Shik Oh ),이성학 ( Sung Hak Lee ),김낙준 ( Nack J. Kim ) 대한금속재료학회 ( 구 대한금속학회 ) 2010 대한금속·재료학회지 Vol.48 No.10

This study assessed the Charpy impact properties of the heat-affected zones (HAZs) of API X80 linepipe steels containing complex oxides. Three types of steel were fabricated by adding Mg and O2 to form complex oxides and their microstructures and Charpy impact properties were investigated. The number of complex oxides increased with the amount of excess Mg and O2 that was included in the steels. Simulated HAZs containing a number of oxides showed a high volume fraction of acicular ferrite (AF) because the oxides acted as nucleation sites for AF, thereby leading to an improvement in the Charpy impact properties. According to a correlation study between the heat input, the volume fraction of the AF, and the Charpy impact properties, ductile fractures occurred predominantly when the fraction of the AF was 20% or higher; moreover, the Charpy absorbed energy was excellent at more than 100 J. These findings suggest that the improvement of the Charpy impact properties of the HAZs was associated with the active nucleation of AF in the oxide-containing steel HAZs.