• Title/Summary/Keyword: growth ring

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The Instability Due to the Parasitic Modes in the Electron Storage Ring (전자저장링에서 고차 모우드에 기인하는 불안정성)

  • 남순권
    • Journal of the Korean Vacuum Society
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    • v.3 no.3
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    • pp.257-263
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    • 1994
  • 전자 저장링에서 고차 모우드에 대한 웨이크 포덴셜 및 임피던스 등이 계산되었고 설계된 고주 파 가속공동에 대한 불안정성에 관한 현상이 포커-프랑크 방정식에 의해 계산되었다. 이 결과로 고차 모우드에 대해서 안정영역을 만족함을 보였으며, 강한 로빈슨 불안정성은 일어나지 않음을 알 수 있었 다. 웨이크 필드를 사용한 threshold가 tracking 에 의해 계산되었고 15개의 고차모우드에 의한 growth rate 가 계산되었다.

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Crystal Growth of LiNbO3 for SAW Devices (SAW Device 응용을 위한 LiNbO3 단결정 성장)

  • 최종건;오근호
    • Journal of the Korean Ceramic Society
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    • v.25 no.1
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    • pp.78-82
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    • 1988
  • Good quality LiNbO3 single crystals which can be applied to SAW devices, were grown by Czochralski method. It was observed that the gas-bubbles were concentrated in ring shape at the outer part of grown crystals, and this anomaly was illustrated by modeling the mechanism of gas-bubble entrapment according to the melt flow pattern in the crucible. And this mechanism was also encertained by observation of solid-liquid interface shape of grown crystals. The optimal condition for good quality crystals was known that the solid-liquid interface shape was slightly concave.

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Stereocontrolled asymmetric synthesis of pancratistatin

  • Park, Je-Eun;Kim, Sang-Hee;Ko , Hyo-Jin
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.362.1-362.1
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    • 2002
  • Pancratistatin is a highly oxygenated phenanthridone alkaloid. exhibits a high level of in vitro and in vivo cancer cell growth in inhibitory activity. and antiviral activity. The asymmetric synthesis of this alkaloid has been. accomplished from the commercially available (R)-(+)-3-Butyn-2-ol. We utilized the Claisen rearrangment and metathesis to install stereogenic centers in the cyclohexene ring that has absolute chemistry. (omitted)

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Increasing Atmospheric Carbon Dioxide and Growth Trends of Korean Subalpine Conifers - Dendrochronological Analysis - (대기중(大氣中) 이산화탄소 증가와 한국산 아고산(亞高山) 침엽수류의 생장동향(生長動向) - 연륜연대학적(年輪年代學的) 분석(分析) -)

  • Park, Won Kyu
    • Journal of Korean Society of Forest Science
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    • v.82 no.1
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    • pp.17-25
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    • 1993
  • Tree-ring data of subalpine conifers growing in Korea were analyzed to evaluate the possibility of enhanced tree growths due to increased atmospheric carbon dioxide. A total of 64 trees of three species(Taxus cuspidata, Pinus koraiensis, Abies koreana) were sampled from three mountain ranges (Seolak, Sobaek, Chiri) at 1200~1750m(above sea level) and four chronologies were developed in spans of 209~412 years. No apparent growth increases were found in the graphs of chronologies. As comparing the growths of 1900-1949 and 1950-1989 period, only one chronology possessed higher mean growth in the post-1950 period. Growth increase found in the Pinus koraiensis chronology from Mt. Seolak was 8% but it could not be solely attributed to increased carbon dioxide concentration.

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Revisiting Use of Growth Factors in Myelodysplastic Syndromes

  • Newman, Kam;Maness-Harris, Lori;El-Hemaidi, Ihab;Akhtari, Mojtaba
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1081-1091
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    • 2012
  • Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematologic neoplasms characterized by morphologic dysplasia, aberrant hematopoiesis and peripheral blood refractory cytopenias. MDS is recognized to be associated with an increased risk of symptomatic anemia, infectious complications and bleeding diathesis, as well as a risk of progression to acute myeloid leukemia, particularly in patients with a high IPSS score. The advent of use of hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) and recombinant erythropoietin (EPO) has improved symptoms in MDS patients in addition to some data that suggest there might be an improvement in survival. G-CSF is an effective therapeutic option in MDS patients, and it should be considered for the management of refractory symptomatic cytopenias. G-CSF and EPO in combination can improve outcomes in appropriate MDS patients such as those with lower-risk MDS and refractory anemia with ring sideroblasts (RARS). This article reviews use of growth factors for lower-risk MDS patients, and examines the data for G-CSF, EPO and thrombopietic growth factors (TPO) that are available or being developed as therapeutic modalities for this challenging disease.

Biological Characterization of Periconicins, Bioactive Secondary Metabolites, Produced by Periconia sp. OBW-15

  • SHIN, DONG-SUN;OH, MI-NA;YANG, HYEONG-CHEOL;OH, KI-BONG
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.216-220
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    • 2005
  • Periconicin A and B, two new fusicoccane diterpenes originally isolated from the cultures of endophytic fungus Periconia sp. OBW-15, were tested by several biological assays. Periconicin A was consistently more active than periconicin B. In an antifungal activity assay, periconicin A showed potent inhibitory activity against the agents of human mycoses, including Candida albicans, Trichophyton mentagrophytes, and T. rubrum, with minimum inhibitory concentration (MIC) in the range of 3.12- 6.25 $\mug$ /ml. In a plant growth regulatory activity assay, periconicins inhibited hypocotyl elongation and root growth of Brassica campestris L. and Raphanus sativus L. At concentrations below 1 μg/ml, however, both compounds accelerated root growth by 110- 135%. From these results, it is apparent that a methyl group positioned in a cyclopentane ring may play an important role in plant and fungal growth inhibitory activity.

The Effects of CO2 Enrichment on the Radial Growth of Pinus densiflora

  • En-Bi CHOI;Hyemin LIM;Jeong-Wook SEO
    • Journal of the Korean Wood Science and Technology
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    • v.52 no.3
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    • pp.289-299
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    • 2024
  • The current study aimed to investigate the impact of CO2 enrichment on the width of annual tree rings, earlywood and latewood, and the area of annual growth of Pinus densiflora Siebold & Zucc. grown in open-top chamber (OTC). To this end, two CO2 enrichment cases were considered, namely 1.4 × increment (560 ppm in OTC-II) and 1.8 × (720 ppm in OTC-III) were compared with the current atmosphere (400 ppm in OTC-I). The CO2 enrichment conditions for a period of 12 years (2010-2021) were considered, and all measurements were done through image analysis. The study showed that the increment in CO2 concentrations positively affected the tree growth. The measurement data from the trees in OTC-III were considerably higher than those from OTC-I, whereas those from OTC-II were slightly higher than those from OTC-I. Decreasing patterns of the measured widths and area in 6-7 years after the beginning of CO2 enrichment was found for all the OTCs. These patterns were possibly due to changes in the physiological features, such as aging. The findings of the present study can have potential uses as fundamental data for forest management considering CO2 concentrations.

Reconfirmation of age and growth of the pointhead flounder, Hippoglossoides pinetorum in the coastal waters of the East Sea off Gyeongbuk (경북 동해안산 용가자미 (Hippoglossoides pinetorum) 연령과 성장의 재확인)

  • JEONG, Yeon Kyu;KIM, Sung Tae;YOON, Sang Chul;YANG, Jae Hyeong;JUNG, Kyung Mi;OH, Taek Yun;CHOI, Kwang Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.4
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    • pp.363-375
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    • 2017
  • The age and growth of pointhead flounder, Hippoglossoides pinetorum caught by gill nets was analyzed in this study from March 2015 to July 2017. New annuli were formed in H. pinetorum otoliths annually, and the boundary was set between the opaque and translucent zones from March and April. The relationships between total length (TL) and body weight (BW) were $BW=0.0025TL^{3.409}$ ($r^2=0.9551$) for females and $BW=0.0057TL^{3.138}$ ($r^2=0.9163$) for males. In this study, the ring of pointhead flounder, H. pinetorum was formed between 3 and 8 for females and between 3 and 6 for males. Total length (TL) and otolith radius (OR) were measured as follows: TL = 7.142 OR + 0.769 ($r^2=0.793$) for females and TL = 6.498 OR + 1.706 ($r^2=0.652$) for males. The mean distances of first ring ($r_1$) were 0.92 mm and 0.91 mm for females and males respectively. The TLs at the time of annulus formation, back-calculated from the otolith-length relationship by reference to the von Bertalanffy growth curves, were $L_t=43.59(1-e^{-0.15(t+0.007)})$ for females and $L_t=28.13(1-e^{-0.26(t+0.006)})$ for males while the growth between female and male was different.

Age and growth of the black rockfish, Sebastes inermis, in the Jeonnam marine ranching area in the southern Sea of Korea (한국 남해 전남바다목장해역 볼락, Sebastes inermis의 연령과 성장)

  • Kim, Hee-Yong;Kim, Sang-Hwa;Huh, Sun-Jung;Seo, Young-Il;Lee, Sun-Gil;Ko, Jun-Chul;Cha, Hyung-Kee;Choi, Mun-Sung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.4
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    • pp.346-357
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    • 2010
  • Characteristics of age and growth of the black rockfish, Sebastes inermis sampled in the Jeonnam Marine Ranching Area (JMRA) around Geumo Islands south of Yeosu were investigated using 642 otoliths from March 2009 to February 2010. The opaque zone was formed in September once a year and hence it was used as an annulus. The parturient period was December to January, and therefore the duration from fertilization to the complete formation of the opaque zone was nineteen months. From the parameters calculated using the average length when the year ring was formed, growth of S. inermis were expressed by von Bertalanffy growth equation as $L_t$=23.267 ($1-e^{-0.4406(t+1.1971)}$) for females and $L_t$=22.030 ($1-e^{-0.5312(t+0.6834)}$) for males when is total length in age t. Through the growth equations, the maximum length was determined as 23.27cm for females and 22.03cm for males and the growth factor as 0.4406/yr and 0.5312/yr, respectively. Finally, the growth of female S. inermis is larger than the one of male S. inermis.