• 한국결정성장학회지
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• 제10권5호
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• pp.356-361
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• 2000

The radial position of OiSF-ring has been meaningful data in industry. Thus it's position was calculated by application of (V/G)/sub crit/ = 0.138 ㎟/minK and point defect dynamics for industrial scale grower with various pull rates. After the calculation, compared with experimental result. OiSF-ring diameters expected with calculation were good agreement with experimental results. In order to show validity of the predicted temperature distribution using STHAMAS which is one of the global simulator for Cz crystal growing, temperature was measured along the axis of crystal using thermocouples, and compared with the calculated temperature. We found the effective thermal conductivity K/sub m/ (r) which gives in accordance with the temperature distribution at the axis of crystal and crystal/melt interface shape between experimental and computational results. Therefore, effective thermal conductivity K/sub m/ (r) was applied instead of solving melt convection problem.

• Archives of Pharmacal Research
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• 제16권1호
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• pp.62-67
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• 1993

A series of 12 pyrimidine derivatives were prepared and tested in vitro against growth, sporulation and nucleic acids of Fusarium oxysporum f. sp. lycopersici and Helminthosporium oryzae. Intorduction of thiazole ring together with two aryl groups to 2-aminopyrimidine induced drastic toxicity for both fungi. Pyrimidine derivatives with aryl groups were less toxic. Nitro groups were found to enhance the toxicity of the pyrimidine derivatives especially when substituted in ortho-position of the aryl groups. Inhibition of nudeic acids synthesis of both fungi was attributed mainly to the presence of thiazole ring.

• 대한기계학회논문집
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• 제8권4호
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• pp.313-320
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• 1984

본 연구에서는 원형 단면 링 압인(circularcross-section ring indentation) 을 노치 주위에 주고 피로 하중하에서 발생한 균열이 성장하는 거동을 관찰하고 해석 하므로써 균열의 저지 및 지연 방법으로써 가능성을 제시하고자 한다.

• 대한기계학회논문집B
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• 제20권10호
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• pp.3322-3333
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• 1996

A numerical analysis has been conducted to investigate a modified floating-zone crystal growth process in which most of the melt surface is covered with a heated ring. The crystal rod is not only pulled downward but rotated around its axisymmetric line during crystal growth process in order to produce the flat interface of crystal growth and the single crystal growth of NaNO3 is considered in 6mm diameter. The present study is made from a full-equation-based analysis considering a pulling velocity in all of solid and liquid domains and both of solid-liquid interfaces are tracked simultaneously with a governing equation in each domain. Numerical results are mainly presented for the comparison of the surface shape of rotational crystal rod with that of no-rotational crystal rod and the effects of revolution speeds of the crystal rod. Results show that the rotation of crystal rod produces more its flat surface. In addition, the shape of crystal growth near the centerline is more concaved with the increase in the revolution speed of crystal rod. The flow pattern and temperature distribution is analyzed and presented in each case. As the pulling velocity of crystal rod is increasing, the free surface of the melt below the heated ring is enlarged due to the crystal interface migrating downward.

• 한국산림과학회지
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• 제84권1호
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• pp.71-76
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• 1995

본 연구는 강원도에 분포하는 소나무를 대상으로 지리적(地理的) 요인(要因)에 의한 소나무 생장권역(生長圈域)을 구분하는데 목적이 있다. 기초자료로는 생장추로 채취한 공시목편의 직경 연년생장량(連年生長量)의 실측치를 이용하였다. 실측된 연년생장량내의 개체간 변이를 표준화(標準化) 과정을 통해 제거하였고 표준화된 값으로 지역별 평균연대기(平均年代期)를 산출하였다. 지역별 평균연대기들을 집락분석(集落分析)하여 직경의 연년생장 패턴에 따라 생장지역을 구분하였다. 분석결과 영동과 영서지방 소나무의 연년생장 패턴이 지리적 분포와 유사한 경향을 보였다. 또한 영서내륙지방은 지리적 요인에 따른 생장패턴의 변이가 큰 것으로 나타났다.

• The Korean Journal of Ecology
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• 제16권3호
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• pp.317-327
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• 1993

Stands profiles, yearly changes in growth of annual rings, age and diameter structure, and spatial distribution pattern of individuals in the Pinus densiflora stands around the Yeocheon industrial complex were investigated. Growth of annual ring in Pinus densiflora, which survived when vegetation of this area was damaged by air pollutants, was suppressed for about 10 years since 1974 when factories in this area began to operate, but since then such suppressed growth tended to be recovered. It was supposed that the suppresed growth was originated from air pollution and that improvement of growth since the suppressed period was due to the release from competition with them by death of neighbouring trees and the resuction of the amount of air pollutants. Physiognomy of Pinus densiflora stands showed mosaic pattern composed of different patches. Spatial distribution pattern of individuals an stand profiles were similar to those of Pinus densiflora stands regenerated after natural and artificial disturbances. In an age distribution diagram, age of Pinus densiflora population ranged from 1 to 33 years, Among these individuals were recrited corresponded to the suppresed period of growth of annual ring in Pinus densiflora survived when the vegetation was damaged by air pollution. On the other hand, from the result of analysis of frequency distribution diagram of diameter, it was postulated that even if whis Pinus densiflora community can be maintained as it is for the time being, it might be changed to Quercus community with the lapse of time. Regeneration; Pinus densiflora; Air pollution; Annual ring; Age structure; Diameter structure; Quercus spp. In these analyses, factors for individual recognition and species recognition were suggested.

• 한국기후변화학회지
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• 제6권4호
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• pp.379-388
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• 2015

The purpose of the this study was to provide basic data on reasonable management for Abies koreana in Mt. Jiri through analysis the ecological characteristics of Abies koreana forests on Seseok. Due to low soil pH (4.26), high organic matter (10.5%) and total N (0.32%), the soil properties of A. koreana forest on Seseok are different from those of other forest soil in Korea. According to the result of importance value analysis, A. koreana (70.5) for tree layer, A. koreana (37.6) and Rhododendron schlippenbachii (20.8) for subtree layer and A. koreana (12.6), Sasa borealis (11.5) and Acer pseudosieboldianum (11.2) for shrub layer were high, respectively. The species diversity of Shannon was 0.425 for tree layer, 0.869 for subtree layer and 1.320 for shrub layer. Evenness and dominance for all layers ranged from 0.365 to 0.894 and 0.187 to 0.635, respectively. Height growth according to DBH of A. koreana on Seseok was relative high. Annual mean tree ring growth of A. koreana showed up 1.372, 1.557 and 1.483 mm/yr for small, middle and large diameter tree, respectively. Considering the importance value, distribution of seedling, height growth and ring growth, A. koreana forest on Seseok in Mt. Jiri will be maintained as the major population from now on.

• Journal of the Korean Wood Science and Technology
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• 제41권5호
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• pp.406-414
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• 2013

This study aims to date wooden coffins excavated from graves in Shinnae-dong, Seoul, South Korea, using dendrochronology. The species of woods used to make the coffins were identified as Pinus densiflora S. et Z., one of the major conifers in Korea. Of 12 graves, 10 were successfully dated using various red-pine chronologies of South Korea. Due to the absence of the last-formed tree ring before felling, the number of sapwood rings, used to obtain likely cutting dates, had to be estimated. The terminus post quem for two coffins without plaster frames were AD 1548 and AD 1571, respectively. Eight coffins with plaster frames yielded estimated dates from AD 1664 to AD 1799. The tree-ring dates indicated that the coffins with plaster frames in Shinnae-dong were constructed approximately 100 years later than those without plaster frames.

• 한국제4기학회지
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• 제17권2호
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• pp.157-159
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• 2003

Much of northern Asia is lacking in high-resolution palaeoclimatic data coverage. This vast region thus represents a sizeable gap in data sets used to reconstruct hemispheric-scale temperature trends for the past millennium. To improve coverage, we present a regional-scale composite of four tree-ring width records of Siberian pine and Siberian larch from temperature-sensitive alpine timber-line sites in Mongolia. The chronologies load closely in principal components analysis (PCA) with the first eigenvector accounting for over 53% of the variance from ad 1450 to 1998. The 20-year interval from 1974 to 1993 is the highest such growth period in this composite record, and 17 of the 20 highest growth years have occurred since 1946. Thus these trees, unlike those recently described at some northern sites, do not appear to have lost their temperature sensitivity, and suggest that recent decades have been some of the warmest in the past 500 years for this region. There are, however, comparable periods of inferred, local warmth for individual sites, e.g., in 1520-1580 and 1760-1790. The percent common variance between chronologies has increased through time and is highest (66.1%) in the present century. Although there are obvious differences among the individual chronologies, this result suggests a coherent signal which we consider to be related to temperature. The PCA scores show trends which strongly resemble those seen in recent temperature reconstructions for the Northern Hemisphere, very few of which included representation from Eurasia east of the Ural Mountains. The Mongolia series therefore provides independent corroboration for these reconstructions and their indications of unusual wanning during the twentieth century.

• 한국농림기상학회지
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• 제18권3호
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• pp.109-119
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• 2016

본 연구는 우리나라의 대표 활엽수종 중의 하나인 신갈나무를 대상으로 기후변화에 의한 연도별 생장도일의 변화가 잠재분포 및 생장에 미치는 영향을 평가하기 위해 수행하였다. 이를 위해 신갈나무 분포 지역의 기후특성을 반영한 군집분석을 실시하였으며, 그 결과 7개의 기후군집으로 분류되었다. 각 군집에 포함된 시군에서 수집된 일평균기온 자료를 기반으로 1951년부터 2010년까지 60년 동안의 연도별 생장도일과 기온효과지수를 산출함으로써 시간 경과에 따른 신갈나무의 잠재분포 범위와 생장의 변화 추이를 평가하였다. 이와 함께 기후변화 시나리오 RCP 4.5와 RCP 8.5를 적용하여 2011년부터 2100년까지 연도별 생장도일과 온도효과지수를 산출하여, 기후변화에 의한 신갈나무의 잠재분포 범위와 생장의 변화를 예측하였다. 신갈나무가 현재 분포하고 있는 지역의 생장도일을 연도별로 산출하여 비교한 결과 위도와 해발고도가 낮은 지역은 시간이 경과함에 따라 신갈나무에 적합한 생육가능 범위를 벗어나는 것으로 분석되었다. 특히 기후변화 시나리오를 적용할 경우 지속적인 기온의 상승으로 인해 2050년 이후에는 잠재분포의 변화뿐만 아니라 생장에도 큰 지장을 주는 것으로 평가되었다.