• 한국약용작물학회지
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• 제23권4호
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• pp.284-291
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• 2015

This study was performed to investigate the effects of enhanced light transmission on plant growth, photosynthetic ability, and disease tolerance to leaf blight, anthracnose in ginseng (Panax ginseng C. A. Meyer, Araliacease family) during the early growth stage (April to June). The photosynthetic ratio, stomatal conductance, and stem diameter of plants grown under a shade net with 15% light transmission rate showed an increasing trend compared to the control plants (5% light transmission rate) although the growth of the aerial parts were not influenced significantly. Plant height, stem length, and leaf length of treated plants were not significantly different from those of the control plants. Root parameters, such as root length, diameter, and weight of treated plants increased significantly compared to the control. Yield performance ($187.4kg{\cdot}10a^{-1}$) of treated plants was 55.5% higher than that of the control ($150.4kg{\cdot}10a^{-1}$). Additionally, disease severity scores of treated plants were lower than those of the control plants, revealing higher survival rates. To retain high yield potential and enhance the level of disease tolerance in ginseng, we suggest the increase of light transmission rate during the early growth stage.

• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.155-163
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• 1999

Heavy metal accumulation in living organisms through food-wed can give serious damage on physiological responses for vital activities. The initiation of heavy metal supposed to begin from the bio-accumulation of plants. To establish basic data fur heavy metal contents in plants at the area without artificial contamination, both woody and herb plants at Mt. Kwang-Duk were studied. The content of heavy metals in various organs of plants were analyzed by ICP. The range of heavy metals in plants for Al, As, Cd, Co, Cr, Cu, Fe. Mn, Pb, Se and Zn were 1.019∼257.200ppm, O∼2.929ppm, 0∼0.079ppm, 0∼0.054ppm, 0.023∼3.007ppm, 0∼1.997ppm, 2.031∼148.500ppm, 1.069∼51.320ppm, O∼126.900ppm, 0.708∼4.927ppm and 0.846∼4.949ppm, respectively. The amount of heavy metals in plants are much less than that of soil except some species. In woody plants, it was detected that the metal contents of leaves were higher than that of stems especially in case of Al and Fe with statistical significance. There were significant differences between shoots and roots of herb plants in metal content of Al, Co and Fe. Those metals have more accumulated in roots comparing with shoots. Some species of plants had shown the difference tendency of heavy metal accumulation. Generally, most species had not exceeded over twice of mean value each other, and had various difference according to the kinds of heavy metals.

• 생약학회지
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• 제18권1호
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• pp.1-4
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• 1987

The methanol and benzene extracts of the leaves of 55 higher plants in Korea were tested for their antibacterial activity against three Gram positive bacteria, Streptococcus mutans, Staphylococcus aureus and Bacillus subtilis, and one Gram negative bacterium Escherichia coli. Among them, the methanol extract of the leaves of Liriodendron tulipifera showed remarkably potent antibacterial activity against both Gram positive and negative bacteria.

• KEPCO Journal on Electric Power and Energy
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• 제2권4호
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• pp.525-529
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• 2016

바이오매스 혼소는 신재생 에너지의 비중을 늘리면서 석탄화력발전에서의 $CO_2$ 배출을 저감할 수 있는 단중기적으로 가장 효과적인 방법이다. 본 논문에서는 이 중 기존 화력발전소에 가장 적은 초기투자비로 적용할 수 있는 직접 혼소법에 대하여 주로 고찰을 수행하고, 국내외 현황 및 전망에 대해 기술하였다. 직접 혼소법은 바이오매스 전용 미분기를 사용하여 혼소율을 늘리는 방법과 저 혼소율에서 초기투자비를 최소화하는 기존 석탄 미분기 사용 바이오매스 혼소법으로 나눌 수 있다. 유럽 및 미국에서는 혼소율을 높이기 위해 많은 상용발전소에서 바이오매스 전용 미분기를 사용하여 10~20% 가량의 혼소율(열량 기준)로 운전을 수행하고 있으나, 국내의 경우에는 RPS 대응을 위해 3~5% 가량의 혼소율에서 기존 석탄 미분기를 그대로 사용하여 바이오매스 혼소를 수행하고 있다. 신기후체제가 시작되고 석탄화력발전에서의 $CO_2$ 저감 요구가 점점 더 증대될 것으로 예상되는 바, 향후 바이오매스 고혼소율이 수행될 수 있는 기술적/저책적 방안이 모색되어야 하며, 이 경우 발생할 수 있는 설비에의 악영향을 면밀히 고려한 연료 표준화 및 전처리 기술이 개발되어야 한다.

• Journal of Plant Biotechnology
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• 제38권1호
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• pp.54-61
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• 2011

에틸렌 생합성 효소인 ACC oxidase 유전자인 CAO cDNA가 antisense 방향으로 도입된 형질전환 담배 식물체는 endogenous한 NtACO의 발현 및 에틸렌 생합성이 모두 억제되었다. 또한 폴리아민 생합성 효소인 SAMDC의 유전자 발현 및 효소 활성이 증가하였고 spermidine 함량이 증가하였다. 이러한 결과는 에틸렌 생합성의 감소로 인하여 세포 내 폴리아민 함량의 변화가 유도되는 경쟁적 관계로 spermidine이 증가하였고 이것은 SAMDC의 발현 및 활성 증가를 유도하였다고 여겨진다. 또한 이들 형질전환 식물체는 담배 역병균에 대한 저항 효과 뿐만 아니라 PR 단백질의 유전자들의 발현양이 증가하였는데 이는 에틸렌 감소에 유도되는 폴리아민 중에서도 spermidine의 증가가 PR 단백질의 유전자들의 발현을 촉진시키고 그 결과 병원균 감염에 대한 저항성을 유도하는 기작이 작동한 것으로 여겨진다. Spermidine을 합성하는데 중요하게 작용하는 SAMDC의 활성을 억제하는 MGBG를 처리한 경우에는 PR1a 발현이 억제된 경우에서 이 기작의 가능성을 확인하였다. 결론적으로 병원균 감염에 대한 과정에서 spermidine의 생합성이 증가하게 되면 PR 단백질 등 스트레스 저항성 관련 단백질들이 유도되어 스트레스 저항성을 높일 수 있을 것으로 사료된다.

• 한국초지조사료학회지
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• 제9권3호
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• pp.179-186
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• 1989

사초용유채의 품종선별선급실험과 유채용유채와 사초용유채품종들 간에 있어서 생산성과 영양가치를 비교한 실험에서 사초용유채 도인품종중 우리나라 남부지역의 특성에 적합한 품종으로 Velox가 사초생산성 및 영양가치면에서 가장 유망하다고 생각되었다. 따라서 Velox를 공시하여 고립적배와 실행群落培 사이에 생산성과 영양가치에 있어서 어떤 차이가 있는가를 비교하였으며 또한 생육과정중의 영양가치의 변화를 조사하였는데 그 결과를 요약하면 다음과 같다. 1. 수당 생산성에 있어서 생체중과 건물중의 개체간 변이가 매우 컸으나 고립적배가 군락적배보다 1%수준의 유의차로 우수하였다. 孤립적배에 있어서 생체중과 건물중의 구성은 분지에 크게 의존되었으며 군락적배에 있어서는 분치와 주경이 비슷한 영향을 주었다. 건물율은 고리적배와 군락적배사이에 큰 차이가 없었으며 부위별로는 주경이 가장 높았다. 2. 粗蛋白質含量은 生育期間이 經過됨에 따라 점차 저하되었으며, 播種後 90일부터 120일까지에는 孤立적배가 群落적배보다 높은 반면 180일以後 개화기까지는 군락적배가 고립적배보다 높았다. NDF, ADF, cellulose 및 lignin등의 鐵維含量은 生育초기에는 낮은 水준이었으며 생育期間이 經過됨에 따라 점차 높아지면서 생育後期에는 孤立적배가 군락적배보다 높게 變化되었다. 3. In vitro 乾物소화率은 줄기나 잎 모두 生育기간이 경과됨에 따라 점차 저하되었으며, 줄기는 군락적배가 고립적배보다 높았으나 잎은 고립적배와 군락적배간에 유의차가 인정되지 않았다.

• Journal of Plant Biology
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• 제12권1호
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• pp.22-30
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• 1969

To investigate the effects of internal radiation of various intensityon the test crop(flax), seeds of four levels of activity($15.5{\times}10-4 $\mu$c/grain, 9.0{\times}10-2$\mu$c/grain, 2.2{\times}100$\mu$c/grain and 3.8{\times}10-1$\mu$c/grain)$ which had been obtained by immersing them into various concentrations of P-32 original solution (total activity: 90 mc, To: 3/21) for 24 hours at room temperature, were germinated, transplanted later into pots, and the rate of germination and the successive growth were observed, and the inorganic conents of the plant top were analyzed. The results are as follows: 1. At the early stage of germination, the plants manifested themselves both inhibitory and promotive effects at higher and lower activity levels respectively, compared those of the control. These difference of growth on account of different levels of activity appeared, however, to be gradually narrowed in the course of time after germination, except at the highest activity. 2. Two weeks after transplanting, the plants of the lowest activity showed more vigorous growth than those of control. The plants belonging to the other activity levels on the other hand, tended to be less growing, the higher the activity. However, this growth gap between treatments seemed to be progressively closed one month after transplanting. 3. Most of the leaves and stems of the plants belonging to the highest activity level ($3.8{\times}101$\mu$c/grain$) were withered during the early stage of growth, and this damage did not recover. 4. Practically no difference of growth was observed among treatments(excluding that of highest activity) one and half months after transplanting. 5. The fluorescence tended to be mroe delayed than the control, as the activity decreased. 6. There was a tendency that the number of pods harvested were larger in the plants treated with P-32 than that of the control. 7. The proportion of fiber in the plants at harvest appeared to be larger at lower activity and smaller at higher P-32 concentration than that of control. 8. As for the inorganic contents of the plant top harvested the floowing tendency was observed: (1) Nitrogen content was highest at the highest activity level at which the poorest growth ensued. (2) There was no clear difference of phosphorus content among treatments. (3) The contents of potassium and magnesium were higher than control at the medium levels of activity. (4) Calcium content of all treated blocks was found to be more than that of control.

• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.111-121
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• 2020

The study measures the resource use efficiency of diesel based power generation in the Maldives and analyses factors which influence efficiency levels. Stochastic frontier analysis (SFA) technique is applied to data on 30 plants over two year period from 2016 to 2017. The study finds that technical efficiency scores varies from 0.44 to 0.98 across power plants. About 33 percent of the plants have scores below the mean technical efficiency score of 0.87. Empirical results indicate ownership and use of solar photovoltaic (PV) have an influence on improving efficiency levels. Privately owned power plants in resort islands obtained higher technical efficiency scores compared to public and community owned power plants. This is a significant finding as the first study that used power plants in tourist sector in a comparative study. Size of the power plants was not found significant, but relatively small installed capacities can also be efficient. This finding is important because in many inhabited islands installed capacities remain oversized compared to the load. The benchmarking exercise offers model power plants that are relatively efficient, for other power plants and policy makers in small islands to learn from.

• Mycobiology
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• 제32권2호
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• pp.79-87
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• 2004

An experiment was carried out to investigate the effects of pre-inoculation with the mycorrhizal fungus Glomus clarum and foliar application of kinetin on the growth of mungbean plant irrigated wht different dilution of seawater. Arbuscular-mycorrhizal(AM) infection significantly increased dry weight, height, chlorophyll, sugar and protein content, nitrogen and phosphorus-use efficiencies, leaf conductivity, transpiration rate, nitrogenase, acid and alkaline phosphates activities of all salinized mungbean plants in comparison with control and non-mycorrhizal plants irrespective of the presence or absence of kinetin. Mycorrrhizal plants showed higher concentrations of N, P, K, Ca and Mg and lower Na/N, Na/P, Na/K, Na/Ca and Na/Mg ratios than non-mycorrhizal plants when irrigated with certain dilution of seawater. Mungbean plants showed 597% and 770% dependency on AM fungus G. clarum in absence and presence of kinetin, respectively, for biomass production under a level of 30% of seawater. The average value of tolerance index for mycorrhizal plants accounted 267% and 364% in absence and presence kinetin respectively. This study provides evidence for the benefits of kinetin which are actually known for mycorrhizal than non-mycorrhzal plants. AM fungus and kinetin protected the host plants against the detrimental effects of salt. However, mycorrhizal infection was much more effective than kinetin applications. Thus management applications of this arbuscular mycorrhizal endophyte(G. clarum) with kinetin could be of importance in using seawater in certain dilution for irrigation in agriculture.

• 한국연초학회지
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• 제19권2호
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• pp.77-82
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• 1997

In order to investigate biochemical activities of harvested tobacco leaves, photosynthetic rate, soluble protein contents, and peroxidale activities were analysed during different maturing period. Physiological activities of harvested leaves during maturing period were higher in topped than those of non-topped plants. Chlorophyll content and photosynthetic rate in both topped and non-topped plants decreased at 4 days and 3 days before harvest, respectively. The chloroplast numbers in topped and non-topped plants decreased at 3 days and 5 days before harvest, respectively. Changes of soluble protein and total RNA contents showed similar patterns during maturing period. Soluble protein contents were slightly decreased from 5 days before harvest in topped plants, but decreased drastically from 3 days before harvest in non-topped plants. Not much changes were found in total RNA contents in topped plants until 2 days before harvest, and it was largely decreased after 5 days before harvest in non-topped plants. The peroxidase activities drastically decreased in topped plants and increased in non-topped plants after 3 days before harvest during maturing period. The largest change of biochemical activities in tobacco leaves during maturing periods were observed at 3 days before harvest.