• Molecules and Cells
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• 제38권7호
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• pp.651-656
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• 2015

Plant growth and development are coordinately orchestrated by environmental cues and phytohormones. Light acts as a key environmental factor for fundamental plant growth and physiology through photosensory phytochromes and underlying molecular mechanisms. Although phytochromes are known to possess serine/threonine protein kinase activities, whether they trigger a signal transduction pathway via an intracellular protein kinase network remains unknown. In analyses of mitogen-activated protein kinase kinase (MAPKK, also called MKK) mutants, the mkk3 mutant has shown both a hypersensitive response in plant hormone gibberellin (GA) and a less sensitive response in red light signaling. Surprisingly, light-induced MAPK activation in wild-type (WT) seedlings and constitutive MAPK phosphorylation in dark-grown mkk3 mutant seedlings have also been found, respectively. Therefore, this study suggests that MKK3 acts in negative regulation in darkness and in light-induced MAPK activation during dark-light transition.

• 기술혁신학회지
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• 제17권2호
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• pp.355-379
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• 2014

새로운 에너지 기술이 기존 사회시스템과 공존하며 확산되는 과정은 저탄소 사회로의 전환을 위해 꼭 필요하지만 어려운 여정이다. 정부주도로 추진되고 있는 서남해 2.5GW 해상풍력사업은 대용량 신재생에너지발전을 중앙전력계통으로 연계하는 것을 목표로 추진되고 있다. 따라서 성공적인 해상풍력 발전의 도입을 위해서는 기존 사회기술시스템의 전환도 병행되어야 한다. 본 연구는 다층적 관점과 전략적 니치관리를 방법론으로 해상풍력기술의 니치전략 적용에 대한 에너지 시스템 전환을 분석한다. 연구결과로서 새로운 기술이 기존 레짐(regime) - 환경상황(landscape)과 연계, 소통을 거쳐 성장하는 과정을 다층적으로 분석하고 에너지체제와 신기술의 관계의 변화를 구조화 하였다. 또한 전략적 니치관리 연구를 적용하여 니치실험 착수단계에서 내재하는 장애요인을 진단하고 해상풍력 실증사업 지연의 원인을 파악하였다. 이를 통해 해상풍력 니치기술이 에너지체제와 다양한 제도 속에서 안정적으로 성장할 수 있다는 실천적 시사점을 도출하였다.

• 대한기계학회논문집B
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• 제35권9호
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• pp.923-932
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• 2011

본 연구에서는 복합화력발전소 가스터빈 출구가스 안내덕트 내부의 가스유동장이 배열회수보일러 전열기구에 미치는 영향을 CFD기법을 이용하여 분석하였다. 안내덕트 내부 난류흐름의 경우, 유속의 편차가 크고 선회 효과 및 상승류 현상이 심한 특징을 가지고 있음으로 이와 같은 유동의 수치해석을 위해 2개 방정식 난류점성 모델 중 RNG k-${\epsilon}$ 모델을 사용하였으며 유동장의 영향을 가장 많이 받는 배열 회수보일러 최종과열기관의 열전달특성변화를 파악하기 위하여 NTU 방식을 이용한 수치해석결과와, 산업계에서 적용하는 설계기법에 의한 결과를 비교하였다.

• 한국습지학회지
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• 제17권1호
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• pp.91-100
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• 2015

본 연구의 목적은 남한강, 금강, 낙동강에 존재하는 세 개의 인공습지에 대하여 2012과 2013의 식생변화 모니터링 결과를 비교 분석하고자한다. 각각의 인공습지는 비내섬, 세도지구, 옥포지구로 식생 모니터링 결과를 비교 분석하여 보면, 비내섬 습지의 경우, 버드나무 군락과 물억새 군락이 우점하고 있으며, 수변부의 저지대를 따라 달뿌리풀 군락, 쑥-망초 군락, 환삼덩굴 군락 등이 분포하고 있는 것으로 조사되었다. 주요 식생의 변화를 알아보면 특히, 환삼덩굴 군락은 하절기에 버드나무군락의 임내와 임연부 및 키 낮은 초원을 중심으로 분포역이 크게 증가하는 것으로 조사되었다. 옥포지구 습지는 2012년에 없었던 마름이 2013년 수역에 분포하고 있으며, 정수식물 군락에 분포하고 있는 갈대 군락은 2012년에 비해 2013년 분포역이 축소하였으며, 갯버들 군락은 2012년과 2013년 모두 분포역이 변화하지 않고 서식하고 있는 것으로 조사되었다. 세도지구 습지는 2012년에 조사된 이차초지대는 고수부지에서 인위적 식재로 인해 비수리 군락으로 변화하였으며, 2012년의 대부분의 군락이 2013년에 망초군락이 번성하면서 망초 군락으로 천이되었다. 물억새 군락과 갈대군락은 2012년과 2013년 모두 분포역 변화 없이 서식하는 것으로 조사되었다. 비내섬 습지의 식생은 건성천이보다는 습성천이로 진행될 것으로 판단된다. 옥포지구 습지는 수변식생의 천이과정은 안정화단계에 도달할 때까지 오랜기간 지속적으로 변화될 것으로 예상된다. 세도지구 습지는 건성천이와 습성천이가 병존하고 있으며, 향후 갈대, 물억새와 버드나무군락으로 천이가 예상된다.

• 한국안전학회지
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• 제33권1호
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• pp.7-15
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• 2018

The friction factors according to the flow regimes in helical coil tubes depend on the coil diameter, the tube diameter, and the coil pitch. In previous studies, correlations for the laminar flow regime in helical coil tubes have been proposed. However, studies on the transition flow regime and the turbulent flow regime are insufficient and further researches are necessary. In this study, characteristics of the friction factors for the laminar, transition and turbulent flow regimes in helical coil tubes were experimentally investigated. The helical coil tubes used in the experiments were made of copper. The curvature ratios of the helical coil tubes, which means the ratio of helical coil diameter to inner diameter of the helical coil tube are 24.5 and 90.9. Experiments were carried out in the range of $529{\leq}Re{\leq}39,406$ to observe the flows from the laminar to the turbulent regime. The friction factors were obtained by measuring the differential pressures according to the flow rates in the helical coil tubes while varying the curvature ratios of the helical coil tubes. Experimental data show that the friction factors for the helical coil tube with 24.5 in the curvature ratio of the helical coil tube were larger than those in the straight tube in all flow regimes. As the curvature ratio of the helical coil tube increases, the friction factor in turbulent flow regime tends to be equal to that of the straight tube. In addition, it was confirmed that the transition flow regimes in the helical coil tubes were much wider than those in the straight tube, also the critical Reynolds numbers were larger than those in the straight tube. The results obtained in this experimental study can be used as basic data for studies on the water hammer phenomenon in helical coil tubes.

• 연구논문집
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• 통권24호
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• pp.119-128
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• 1994

A special steels have been developed for the possible applications of turbine blade in nuclear power plant. The compositions of developed alloy were selected by the reference of imported alloy. The various properties such as tensile property, impact energy, hardness, and microstructures were investigated. All the properties of optimum heat treated materials were satisfied with the present specifications of turbine blade materials in unclear power plant. Furthermore, FATT(Fracture appearance transition temperature), high temperature tensile properties, and transformation temperatures of developed alloy also have been studied.

• Journal of Plant Biology
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• 제33권4호
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• pp.285-292
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• 1990

In order to elucidate the formation of reaction tissues during the transition from primary to secondary growth, the developmental anatomy was conducted in the first internode of Ginkgo biloba seedling in horizontal position. The righting of the horizontal first internode took place at the middle portion and gradually proceeded to the base during the primary growth. Reaction tissues were formed corresponding to the righting movement in the horizontal first internode. During the transition from primary to secondary growth, compression wood was gradually developed on the lower side only. The anatomical features of compression wood also extended longitudinally to the lower side of the vertical portion where it coincided with the lower side of the horizontal first internode occurs acropetally from basal to apical portion. Eventually, some of the anatomical features of compression wood occurred at the primary growth. And the typical compression wood is gradually established during the secondary growth. On the other hand, the lower side tracheid and ray were longer and higher than those of the upper side in the horizontal first internode. However, difference in the width of ray was not observed between the lower and upper sides.

• Journal of Plant Biology
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• 제27권1호
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• pp.15-24
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• 1984

Leaf venation of 12 species of Lauraceae in Korea, native or introduced, was investigated and described by the use of Soft X-Ray. They could be grouped by the venation types, such as, 1. Actinodromous; Lindera obtusiloba, 2. Acrodromous; Cinnamomum camphora, C. japonicum, C. loureirii, 3. Brochidodromous having strongly developed basal secondary vein; Neolitsea aciculata, N. sericea, 4. Brochidodromous hoving irregulary branched secondary vein; Lindera erythrocarpa, L. glauca, 5. Brochidodromous having weak marginal loop; Machilus thunbergii, M.Japonica, 6. Brochidodromous having typical venation; Iozoste lancifolia, Litsea japonicum. This grouping corresponded with current classifying system at genus level except for genus Lindera, and supported Nakai's system at Tribe level. They also showed a gradual transition from brochidodromous to actinodromous types, but to certify the systematic value of this transition warrented more study. Identifying key for the species could be made by the venation type.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1475-1477
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• 2003

The satellite remote sensing data is good in order to grasp the wide natural environment. The purpose of study is that it examines spectral reflection characteristic and vegetation index by the utilization of the plant energy ( chlorophyll ) for examining the reliability of satellite data and grasps the transition of the natural environment using the result. According to result of analysis, there were NDVI and mutual relationship on chlorophyll, and luminance compensation of NDVI was effective for all area. In vegetation transition, there were no luminance compensation and relation, and there was a decrease of vegetation in area in south and north. The reason was a result by the artificial and natural effect. This analysis is an effective method in order to confirm the change of specific vegetation.

• Journal of Contemporary Eastern Asia
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• 제18권1호
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• pp.153-174
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• 2019

South Korea's energy policy has been historically established through an energy production structure that relies on thermal and nuclear power generation in relation to a centralized 'Hard Energy System'. However, climate change issues are forcing the transition to renewable energy, and it is crucial for local governments to enable this. This study analyses Seoul city's local energy governance, which is known as One Less Nuclear Power Plant Initiative, by applying the collaborative governance framework inspired by Ansell and Gash (2008) and the Reflexivity framework of Confucianism. It is considered that the local energy governance model of Seoul city can be used as a model by other local governments, and it will eventually lead to a decentralized energy system in this era of energy transition.