• 한국초지조사료학회지
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• 제20권4호
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• pp.265-274
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• 2000

To investigate the effects of anion replacement on NO3- concentration in Italian ryegrass. Plants weregrown hydroponically to the full vegetative stage. NO3 supply(control) was replaced with SO1- (Tl), C1-(T2) and water (T3) to during 14 days. The determination of inorganic nutrient uptake and quantification ofprincipal metabolites (nitrate. protein and sugar) followed. Relatively high uptake of ~ a a'n d Ca" for controlplants, K+ and POJ- for T2 plants, and C 1 for TI plants was observed, respectively. Proteins in shoot andstubble were relatively higher in control and TI plants, which coupled N source. In root proteins largelydecreased (especially in T3 plants) during experimental period. Sugars in shoot of all four treatments tendedto decrease during the first 7 days and recovered afterward. Sugars in stubble also markedly decreased duringthe first 7 days, while those in root was much less varied during experimental period. After 14 days oftreatment, nitrate concentration in shoot of control plants was 13mgIg FW. Comparing to control: nitrate inshoot reduced by 27%, 46% and 50% in TI, T2 and T3 plants, respectively. Dry weight was slightlyincreased or not significantly changed in control, T1 and T2 plants, while a significant decrease(31.3% ofcontrol) occurred in T3 plants.(Key words : Italian ryegrass, Anion replacement, Ion uptake, Protein, Sugar, Nitrate)ptake, Protein, Sugar, Nitrate)

• 한국농공학회지
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• 제32권E호
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• pp.1-19
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• 1990

Abstract Over the last several decades, crop production in the United States increased largely due to the extensive use of animal waste and fertilizers as plant nutrient supplements, and pesticides for crops pests and weed control. Without the application of animal waste best management, the use of animal waste can result in nonpoint source pollution from agricultural land area. In order to increase nutrient levels and decrease contamination from agricultural lands, nonpoint source pollution is responsible for water quality degradation. Nonpoint source pollutants such as animal waste, ferilizers, and pesticides are transported primarily through runoff from agricultural areas. Nutrients, primarily nitrogen and phosphorus, can be a major water quality problem because they cause eutrophic algae growth. In 1985, it was presented that Watershed/Water Quality Monitoring for Evaluation BMP Effectiveness was implemented for Nomini Creek Watershed, located in Westmoreland County, Virginia. The watershed is predominantly agricultural and has an aerial extent of 1505 ha of land, with 43% under cropland, 54% under woodland, and 3% as homestead and roads. Rainfall data was collected at the watershed from raingages located at sites PNI through PN 7. Streams at stations QN I and QN2 were being measured with V-notch weirs. Water levels at the stream was measured using an FW-l Belfort (Friez FWl). The water quality monitoring system was designed to provide comprehensive assessment of the quality of storm runoff and baseflow as influenced by changes in landuse, agronomic, and cultural practices ill the watershed. As this study was concerned with the Nomini Creek Watershed, the separation of storm runoff and baseflow measured at QNI and QN2 was given by the master depletion curve method, and the loadings of baseflow and storm runoff for TN (Total Nitrogen) and TP (Total Phosphorus) were analyzed from 1987 through 1989. The results were studied for the best management practices to reduce contamination and loss of nutrients, (e.g., total nitrogen and total phosphorus) by nonpoint source pollution from agricultural lands.

• Journal of Astronomy and Space Sciences
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• 제23권2호
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• pp.153-160
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• 2006

이 논문에서는 적외선 우주관측을 위한 냉각시스템 시험모델(PSICS, Protomodel Space Infrared Cryogenic System)의 설계를 위해 수행된 열해석 및 열설계 내용을 논의한다. 이 냉각시스템은 장래 진행될 위성 탑제용 적외선 우주 망원경의 냉각시스템 계발을 위한 예비연구를 위한 시스템이며, 테스트는 지상에서의 관측을 통해 수행된다. 냉각목표 온도는 80K이고, 80K에서 500mW의 냉각능력을 갖는 스터링 냉동기 1대가 냉각에 사용된다. 저열침입과 열부하의 바른 예측을 위해 냉각시스템의 전도, 복사 등의 각 열전달 모드에 대해 열부하를 산출하였고, 총 열부하는 복사열 차단 정도에 따라 $42{\sim}149mW$임을 알았다. 또한 냉각박스 표면의 온도분포는 0.12K 이하의 균일한 온도분포로 유지될 수 있음을 알았다. 이를 통해 80K에서 500mW의 냉동기를 이용하여 충분히 냉각시킬 수 있음을 확인하였다.

• 대한치과기공학회지
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• 제31권4호
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• pp.37-43
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• 2009

This study evaluated the effect of concentration of glass fiber reinforcement on the flexural properties of auto and heat polymerized denture base resin. The test specimens($64{\times}10{\times}3.3mm$) were made of auto and heat polymerized resin(Vertex, Dentimax, Netherlands). Glass fiber(ER 270FW, Hankuk Fiber Glass, Korea) were used to reinforce the denture base resin. The 2.6%, 5.3% and 7.9% volume pre-impregnated fiber were located at the bottom of specimen. The test specimens(n=7) of each group were stored in distilled water at $37^{\circ}C$ for 50 hours before test. The flexural strength and modulus were measured by an universal testing machine(Z020, Zwick, Germany) at a crosshead speed of 5 mm/min in a three-point bending mode. The data was analyzed by one-way ANOVA and the Duncan's multiple range test(${\alpha}$=0.05). The difference of auto polymerized resin groups and heat polymerized resin groups were statistically analyzed by t-test(${\alpha}$=0.05). Glass fiber showed significant reinforcing effects on auto and heat polymerized resin. For flexural strength and modulus, auto polymerized resin was the highest in 7.9% volume, while heat polymerized resin was the highest in 5.3% volume. In this study, glass fiber at 7.9% volume ratio showed most effective reinforcing effect on auto polymerized resin and glass fiber at 5.3% volume ratio showed most effective reinforcing effect on heat polymerized resin in terms of flexural strength and flexural modulus.

• 원예과학기술지
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• 제31권2호
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• pp.231-238
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• 2013

Perilla frutescens, which comprises var. frutescens and var. crispa, has been cultivated traditionally in Asian countries as an edible oil, leaf vegetable, and medicinal crop. To evaluate the lipophilic phytonutrient properties of P. frutescens, we selected 54 Perilla accessions [19 landraces of var. frutescens (FL), 22 weedy type var. frutescens (FW), 9 weedy type var. crispa (CW), 2 cultivars of var. frutescens widely cultivated for seed oil (FCS), and 2 cultivars of var. frutescens cultivated as a leaf vegetable (FCL)] and analyzed their seeds and leaves for vitamin E, squalene, and phytosterols. Among the four vitamin E isomers analyzed, ${\gamma}$-tocopherol was the major form of vitamin E in seeds, whereas ${\alpha}$-tocopherol was the major form in leaves of all types of P. frutescens. The highest total vitamin E content in seeds was present in FL ($170.0mg{\cdot}kg^{-1}$), whereas that in leaves was highest in FCL ($358.1mg{\cdot}kg^{-1}$). The highest levels of squalene in seeds and leaves were in FL ($65.5mg{\cdot}kg^{-1}$) and CW ($719.3mg{\cdot}kg^{-1}$), respectively. Among the three phytosterols, ${\beta}$-sitosterol occurred in the highest amount in both leaves and seeds of all of the crop types. Phytonutrient contents were comparatively higher in leaves than in seeds of all crop types. All of these results suggest that the consumption of leaves and seeds of Perilla crops could be beneficial to human health, as Perilla possesses considerable amounts of various lipophilic compounds.

• 환경생물
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• 제28권1호
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• pp.1-7
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• 2010

Small wetlands in an upland matrix can support diverse vegetation composition that increase both local and regional species richness. In this study we characterize the full range of wetland vegetation in an upland forest landscape at Dumyeong-ri, Gijang-gun, Busan. This wetland index can be calculated with species data, or with community type data as performed. Classified community types were used to describe vegetation at three wetlands and adjacent areas. The communities contained 28 species of vascular plants and 28 species were identified four plant community types. The Pinus densiflora type was dominated by Pinus densiflora and contained only four species. None of the plots had high proportion of standing water. The Carpinus laxiflora type had high obligate upland species (OU) and facultative upland species (FU). The Rhododendron mucronulatum type grew in over half of the plots included Pinus densiflora and Alnus japonica. Some species bother swampy areas adjacent to site C. The Miscanthus sacchariflorus type consisted of seasonal wetlands. The three sites contained nine species with the strongest indicator species being Miscanthus sinensis var. purpurascens, Miscanthus sinensis, Echinochloa crus-galli, and Sagittaria aginashi. This type had the highest proportions of obligate wetland species. Plant species richness averaged 5.069. Shannon-Weaver index of diversity also varied among the community types (F=22.7, df=4, 115), with the types FU having significantly higher value (2.746) than the others (1.057 for type FW and 1.600 for type OU). Regional plans including all of the diverse types of wetland vegetation in upland forests will contribute substantially to the conservation of plant diversity.

• 한국소음진동공학회논문집
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• 제16권3호
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• pp.291-297
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• 2006

The BVI(blade vortex interaction) noise Prediction has been one of the most challenging acoustic analyses in helicopter aeromechanical Phenomenon. It is well known high resolution airloads data with accurate tip vortex positions are necessary for the accurate prediction of this phenomenon. The truly unsteady time-marching free-wake method, which is able to capture the tip vortices instability in hover and axial flights, is expanded with the rotor flapping motion and trim routine to predict unsteady airloads in forward and descent flights. And Farassat formulation 1-A based on the FW-H equation is applied for the noise prediction considering the blade flapping motion. Main objective of this study is to validate the newly developed prediction code. To achieve the objective, the descent flight condition of AH-1 OLS(operational loads survey) configuration is analyzed using present code. The predicted sectional thrust distribution and sectional airloads time histories show the present scheme is able to capture well the unsteady airloads caused by a parallel BVI. Finally, the predicted noise data, observed in two different positions where are 3.44 times of rotor radius far from the hub center, are quite reasonable agreements with the experimental data compared to the other analysis results.

• Journal of Microbiology
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• 제34권2호
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• pp.144-150
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• 1996

During growth of the genetically engineered E. coli CU103 in different media, extracellular DNAs released from the cells were studied. The extracellular DNAs released in the medium were concentrated by an thanol precipitation method and then quantified by a fluorescence method using Hoechst 33258. The released extracellular DNAs were also examined by gel electrophoresis and identified by Southern hybridization for the cloned pcbCD genes. The chromosomal DNAs and recombinant plasmid containing the cloned genes were observed to be released in an exponential growth phase. In Luria-Bertani (LB) broth and MM2-GLUCOSE, 210 and 69 ng/ml of DNAs were detected, respectively, after 3-4 days incubation at $30^{\circ}C$ and at pH 7.0. But the released DNAs were measured to be about 10-15 ng/ml in filtered river water (FW) and Tris-EDTA (TE). The at both $15^{\circ}C$ and $4^{\circ}C$, but the released DNAs were more easily degraded at the higher temperature. The extracellular DNAs were produced about 2 times more at pH 7.0 than at both pH 5.0 and pH 9.0 in MM2-glucose medium at $30^{\circ}C$. Therefore, the extracellular DNAs were found to be released actively from the cells during growth in liquid media.

• 한국환경복원기술학회지
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• 제14권6호
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• pp.71-85
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• 2011

In Okdong coal mine abandoned area, every year large amount of mine wastes have been swept away due to heavy rains in summer. Because pH of coal-mine waste is in the early 4, plant naturally does not grow there due to unfavorable condition for growing plant. This study had an experiment to grow plant for 6 months using Mycorrhizae which can be adapted well in acid soil. As a result of Experiment, In the infected experiment pot, 90% of the plants survived but in case of uninfected experiment pot, only 25% were alive. From Growth Experiment, it appeared that average stem length increase (cm/month), average fresh weight increase ($g^{fw}/month$), average dry weight increase ($g^{dw}/month$) were increased by 60%, 21%, 31% respectively. Especially, Mycorrhizae plays an important role in providing nutrients and water when seeding are established. Mycorrhizae prevents death caused by lack of nutrients and water and helps growth and development of plant when seeding are established in the early stage. This study proved that Mycorrhizae is comparatively effective in plant growth and prevention of erosion in coal-mine abandoned area.

• Applied Biological Chemistry
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• 제33권2호
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• pp.125-128
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• 1990

저온에서 완두유묘 줄기의 유리 IAA 수준과 그 전구체인 트립토판 수준이 저하하므로, IAA수준의 조절 메커니즘을 규명하기 위하여 IAA분해효소계에 미치는 저온의 영향을 조사하였다. $25^{\circ}C$에서 키운 백색 관두유표를 $5^{\circ}C$의 저온으로 옮기면 IAA oxidase와 peroxidase의 수준은 증가하였으며 catalase의 수준은 저하되었고 과산화수소는 축적되어, 전체적으로 IAA분해계가 저온에서 강화되었다. 저온에 놓였던 유묘를 상온으로 옮기면 IAA 분해계는 다시 대조구 수준으로 회복하였다.