• Applied Biological Chemistry
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• v.40 no.3
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• pp.232-237
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• 1997

Soybean plants inoculated Bradrhizobium japonicum MN 110 were grown in outdoor perlite pots with nitrogen free nutrient solution containing 1.0 mM-P(control) and 0.05 mM-P(stress) and harvested at 28, 35, 42 and 49 days after transplanting (DAT) to examine the effect of phosphorus deficiency on ureide concentration of and distribution to diffrent plant organ in nitrogen fixing soybean plant during the vegetative growth. Total dry mass of control plants increased 8.9 fold and that of phosphorus deficient plant increased 2.7 fold during the experimental period. Phosphorus deficiency reduced total phosphorus and nitrogen accumulation by 80%,40% respectively, at 28 DAT and 93%, 84%, respectively, at 49 DAT. Nitrogen concentration was reduced by phosphorus deficiency in all tissues with leaf and stem tissues affected to a greater degree than nodule and root tissues at every sampling date. Phosphorus deficiency significantly reduced soluble reduced-N and ureide-N concentration in leaf and stem but did not affect those in root. The proportion of soluble reduced-N in leaf was reduced from 60% to 50% but increased from 10% to 20% in the roots. The proportion of ureide-N in leaf of control plants was higher than that in phosphorus deficient plants, whereas, roots of phosphorus deficient plants contained a higher propotion of ureide-N than those of control plants. These indicated that phosphorus deficiency not only inhibit nitrogen fixation of nodules but also restrict the translocation of fixed nitrogen out of the root system into the xylem.(Received April 4, 1997; accepted May 2, 1997)

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.1-11
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• 2007

Light is an environmental component inevitably regulating photosynthesis and photo-morphogenesis, which are involved in the plant growth and development. Studies were conducted at the International Rice Research Institute, Philippines in 2004 and 2005, with aims to investigate 1) morphological responses of rice plants to low radiation, 2) morphological alteration of shade-grown plants when exposed to high light intensity, and 3) photosynthetic responses of shade-grown rice plants. Reduction in solar radiation by 40% induced increases in the area on a single leaf basis, biomass partitioning to leaves, and chlorophyll meter readings but brought about retardation of tiller development and decrease in above-ground biomass production of rice varieties. When the shade-grown plants from two weeks of transplanting to panicle initiation were exposed to full solar radiation after panicle initiation, they demonstrated less increase in chlorophyll meter readings and more decrease in leaf nitrogen concentrations from panicle initiation to flowering than control plants that were grown under the ambient solar radiation for whole growth period after transplanting. Shade-grown rice plants exhibited lower carbon assimilation rates but higher internal $CO_2$ concentrations on a single leaf basis than control plants, when measurements for shade-grown rice plants were made under the shading treatments. But when the measurements for shade-grown plants were made under the full solar radiation, light-saturated carbon assimilation rates were similar to control plants. Response of photosynthetic rates to varying light intensities was not considerably different between shading treatments and control. Yield reduction was observed in the shading treatments from panicle initiation to flowering and from flowering to physiological maturity, mainly by less spikelets per panicle and poor grain filling, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.269-276
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• 2019

A semi-greenhouse experiment with field grown soybean (Glycine max L. cv Deawon, Uram, Jinpong, Soyon, Pungsangnamul, and Haewon) was performed in 2018. The experiment was aimed to investigate individual impacts of drought stress on soybean characteristic and seed yield. The three treatments were used in non-water stress (Control) during the soybean growth season, vegetative stage stress (VS), and flowering period stress (FS). Leaf number, LAI, leaf nitrogen concentration, and leaf biomass were decreased by drought at R4. In our study, the number of pods was 33.6% and 40.5% lower, respectively, in control than in VS and FS. In 100 seed weight, was 16.1% and 10.1% lower, respectively, in control than in VS and FS at R8. As a result, seed yield was 39.8% and 45.1% lower, respectively, in control than in VS and FS. Depending on the drought period, Daewon and Haewon showed a large decrease in yield, while Soyon did not change. The results of this study showed that flower and beginning pod setting stage responded more sensitively to the drought period than vegetative stage. Overall, these results demonstrate soybean seed yield formation more sensitive the during the flowing and beginning pod setting stage. We conclude that adequate water supply for pod setting stage, guaranteeing a high seed yield.

• Journal of Korea Water Resources Association
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• v.43 no.1
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• pp.105-117
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• 2010

This paper presents a new and simple technique to perform MUSCL reconstruction for solving 2D shallow water equations. The modified MUSCL scheme uses weighted area ratio to apply non-uniform grid in stead of the previous method that equally distributed the difference of conservation variables to each interface. The suggested method can physically reconstruct conservation variables in case of uniform grid as well as non-uniform grid. In this study, Unsplit scheme applicable to unstructured grid is used and efficient slope limiter of TVD scheme is used to control numerical oscillation which can be occurred in modified MUSCL scheme. For accurate and efficient treatment of bed slope term, the modified MUSCL scheme is coupled with the surface gradient method. The finite volume model applied to suggested scheme is verified through a comparison between numerical solution and laboratory measurements data such as the simulations of isolated building test case and Bellos's dam break test case.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2A
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• pp.181-186
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• 2004

Analysis on sharing between GSO FSS and terrestrial system in the 40㎓ band, related with the problem for sharing between terrestrial services and FSS and identification of HDFSS downlink bands in World Radiocommunication Conference 2003, was practiced by assuming that both systems are operated in Korea. According to results from simulation using the characteristic parameters of GSO FSS and terrestrial FS system in 40 ㎓ described in ITU-R Recommendations, in case that elevation and azimuth angle of antenna of FS station are adjusted to point directly to the geostationary satellite, the GSO system can cause the worst interference to the FS system. This situation is possible to occur in the installation of 40 GHz FS station in urban area where there are high-rise buildings. If high-density FS stations in 40 ㎓ band are operated in the future, interference mitigation techniques to avoid GSO arc should be considered.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.129-132
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• 1988

Ginseng is cultivated in Korea. Japan. China. the Soviet Union and North America. Studies of the macroclimate of each of these producing areas shows that ginseng has certain requirements for production. In each producing area the microclimate is modified in different ways. Comparisons of recent research data from North America. Korea and China is presented in order to define. more precisely. the various microclimate requirements for ginseng production. These include studies of light interception as influenced by different shade materials. In North America. wood. woven black polypropylene and knitted polyethylene shade are used. whereas in China. dried grasses are bound together in layers with wire and polyvinylchloride is inserted between the layers. The influence of these various shade materials in terms of crop grow1h and root yield are presented. The major effect of temperature seems to be on root growth. During much of the growing season optimum temperatures for root grow1h are not reached. Growth analysis data for different age plants are being used to show the effects of different soil temperature regimes on distribution of dry matter between the shoot and root.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.1
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• pp.5-14
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• 2020

The study was initiated to reduce production cost and environmental pollution with the evaluation of nutrient requirement of 'Nero' black chokeberry (Aronia melanocarpa) and optimum amount of oil cake application. 100% of a recommended amount (RA) of oil cake was designated as a 100-RA, with 0-RA, 25-RA, 50-RA, and 75-RA for 0%, 25%, 50%, and 75% RA, respectively. The oil cake was scattered around the black chokeberry at every year for two years from 2018 to 2019, with investigation conducted for the second year. Soil mineral nutrient concentrations were not significantly different among the treatments. Dry weight (DW) of root and leaves was low for 0-RA-treated black chokeberry, with no significant difference observed for the all treatments for the DW of stems. 75-RA increased the fruit DW of 615 g and yield efficiency of 45.3%. Top:root ratio was the highest of 4.7 for 75-RA. Increased amount of oil cake application expanded the tree volume. Tree volume had a strong positive relationship with the root DW (r²=0.977). Mineral nutrient uptake in the root was the highest on the 25-RA-treated black chokeberry, except for Fe uptake. Mineral nutrient uptake in the leaves were similar to all the black chokeberries, except for T-N and Fe uptake. 75-RA increased mineral nutrient uptake in the fruit, except for Cu, in particular, 7.45 g in fruit N, which was the highest level compared to those of the other organs. T-N and P uptake were evenly distributed in the leaves, stems, and fruit, with high K uptake for leaves and fruit. 75-RA maximized to 17.2 g of the total nutrient uptake in a black chokeberry, with 4.9 g for the 0-RA. All mineral nutrient uptake were overall higher on the black chokeberry treated with 50-RA, 75-RA, and 100-RA compared to those of 0-RA and 25-RA.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.385-391
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• 2012

The growth of terminal shoots of persimmon (Diospyros kaki) was analyzed during the first two months from the time of bud sprout to understand the dynamics of their early growth. Field-grown, mature 'Fuyu' and 'Nishimurawase' trees were used in a three-year study at two locations in Gyeongnam province. The growth of terminal shoots was most active from late April, about 10 days after foliation, to early May, followed by a gradual decline by late May. The increase in leaf area continued unabated throughout May. The weight of a flower bud increased slowly until early May and rapidly after flowering. Although its extension growth had been ceased by late May, dry weight (DW) of a terminal shoot continued to increase almost linearly throughout May due to shoot thickening and continued growth of leaves and fruits. In late May, the leaves and the stem accounted for more than 60% and less than 20% of total DW of a shoot respectively; fruit proportion increased to 7 to 17% by then. Relative growth rate (RGR) of the terminal shoot was higher than 213 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late April, but declined to less than 63 $mg{\cdot}g^{-1}{\cdot}d^{-1}$ in late May. Like the pattern of seasonal changes in RGR, net assimilation rate (NAR) of the shoots decreased from 1.9 to 2 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$ to 0.5 to 0.8 $mg{\cdot}cm^{-2}{\cdot}d^{-1}$. An early-season 'Nishimurawase' did not differ from a late-season 'Fuyu' in RGR and NAR during the first two months of growth. The early growth of the shoots was affected mainly by the reserves redistributed from permanent organs, however, environmental conditions at the time was also involved.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.294-300
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• 1996

We performed an experiment to confirm the possibility of wasabi culture using the wat­er of the Soyang River Dam in Chunchon and the ground water in Suwon. Water mineral content of Soyang River except for P was less than that of ground water of Suwon. Dis­solved oxgen and E C of Chunchon was proper to culture wasabi but E C and dissolved oxgen of Suwon was not suitable for that. Water temp. of Soyang river was very changable by month while that of the ground water in Suwon was kept constantly. In Soyang river of Chunchon the month that water temp. show $8{\sim}18^{\circ}C$, optimal growth temp., was May to Nov. and the month that water temp. show less than $6^{\circ}C$, growth limit temp., was $Jan.\;{\sim}\;Feb.$ of Chunchon. Rhizome weight of main stem in Chunchon and Suwon was 63g and 22g per plant and rate of maketable rhizome was each 80%, 0% by culture of 32 months to include raising see­dling period of 13 months. Dry matter partitioning ratio of petiole in Soyang river of Chunchon was the highest of all others but it was lowest of all others in ground water of Suwon. Rhizome weight of main stem in Chunchon was showed possitive correlation with plant height and fresh top weight and in Suwon it was showed possitive correlation with root weight and high possitive correlation with No. of total leaves and No. of tillers.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.224.2-224.2
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• 2010

연료개질기는 연료전지 시스템의 핵심 구성요소 중의 하나로 도시가스로부터 수소를 생산하는 역할을 담당한다. 연료개질기는 주로 탈황, 수증기 개질, 수성가스 전이, 선택적 산화 반응의 4단계로 구성되어 있으며 이 중 상온 탈황부분을 제외한 나머지 부분은 일체화 설계를 통해 제작된다. 탈황의 경우 도시가스에 포함된 부취제인 황화합물를 제거하여 후단에 위치한 촉매층이 황에 의해 피독되는 것을 막는 역할을 하며 주로 상온흡착식 탈황제를 사용한다. 황이 제거된 도시가스는 물과 함께 연료개질기로 도입되어 수증기 개질반응을 통하여 수소, 일산화탄소, 이산화탄소 및 소량의 메탄과 미반응 수증기로 구성된 개질가스로 전환된다. 이후의 수성가스 전이반응에서는 일산화탄소가 물과 반응하여 수소 생산량을 늘리며 동시에 일산화탄소의 농도를 낮추게 된다. 또한 고분자 전해질 연료전지에 공급되는 개질가스는 선택적 산화반응을 통하여 일산화탄소의 농도를 10ppm이하로 유지하게 된다. 이러한 기능의 연료개질기 개발의 주요 이슈로는 컴팩트화 및 고효율화이며 이 두가지 요소를 고려하여 연료개질기를 설계하여야 한다. 연료전지 시스템의 전체부피를 줄이기 위한 노력의 일환으로 연료개질기의 컴팩트화가 요구되는데 가정용 연료전지 기술 선진국인 일본 제품의 경우 $1Nm^3/h$급 연료개질기의 부피는 20L정도로 알려져 있다. 또한 연료전지 시스템의 효율은 연료개질기의 개질효율과 연료전지 스택의 발전효율의 곱으로 계산되기 때문에 연료개질기의 연료개질 효율은 전체 시스템의 효율에 직접적으로 영향을 미치게 된다. 한국에너지기술연구원에서는 수소생산량 기준 $1Nm^3/h$급 연료개질기의 개발을 완료하였으며 크기 및 효율면에서 선진국 제품과 비교하여 동등 또는 우위의 수준을 달성하였다. 연료개질기 내부의 혼합 및 분배 구조를 개선하고 각 촉매층의 최적 배치를 통해 연료개질기의 부피를 최소화 하였으며 연료개질기 내부에서 고온부위와 저온부위 사이의 최적 열교환을 통해 열효율을 극대화 시켰다. 현재 개발된 $1Nm^3/h$급 개질기의 단열 후 부피는 13.5L 그리고 단독운전 시 열효율은 80%(LHV)로 측정되었다. 또한 $1Nm^3/h$급의 연료개질기의 스케일-업 설계를 통하여 수소생산량 3, $5Nm^3/h$ 규모의 연료개질기를 개발하였으며 성능평가가 진행 중이다.