• 한국농공학회논문집
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• 제58권6호
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• pp.1-8
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• 2016

Crop damages due to agricultural drought has been increased in recent years. In Korea, water resources are limited indicating that proper management plans against agricultural drought are required for better water-use efficiency in agriculture. In this study, irrigation intervals and amounts for various crops and soil physical properties (sandy and silt loams) were estimated using the IWMM model. Five different crops (soybean, radish, potato, barley and maize) at the Bangdong-ri site in Chuncheon were selected to test the IWMM model. IWMM assessed agricultural drought conditions using the soil moisture deficit index (SMDI), and irrigation intervals and amounts were determined based on the degree of agricultural drought (SMDI). Additionally, we tested the effects of surface irrigation and sprinkler irrigation methods and various irrigation intervals of 2, 3, 5 and 7 days. In our findings, the irrigation intervals of 5 and 7 days showed the minimum rrigation amounts than others. When we considered that the intervals of 3 or 5 days are usually preferred to fields, the interval of 5 days was determined in our study. The estimated irrigation amounts for different crops were shown as maize > radish > barley > soybean > potato, respectively. The irrigation amounts for maize and barley were highly affected by soil properties, but other crops have less differences. Also, small differences in irrigation amounts were shown between the surface and sprinkler irrigation methods. These might be due to the lack of consideration of water loss (e.g., evapotranspiration, infiltration, etc.) in IWMM indicating model structural uncertainties. Thus, possible water loss (e.g., evapotranspiration, infiltration) need to be considered in application to fields. Overall, IWMM performed well in determining the irrigation intervals and amounts based on the degree of agricultural drought conditions (SMDI). Thus, the IWMM model can be useful for efficient agricultural water resources management in regions at where available water resources are limited.

• 한국축산식품학회지
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• 제40권6호
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• pp.1044-1054
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• 2020

This study was performed to investigate the effects of lotus leaf hot water extracts treatment on the quality and stability of eggs using impregnation treatment through ultrasonication during storage. A total of 480 eggs were categorized into four treatment groups (n=30 each)-non-treated (CON), soaked for 30 min in lotus leaf hot water extracts without ultrasonication (T1), sonicated in distilled water (T2), and sonicated in lotus leaf hot water extracts (T3)-and stored for 15 d at 30℃. The egg weight, Haugh unit (HU), egg grade, albumen height, yolk color, eggshell thickness, eggshell breaking strength, and weight loss were measured for egg quality assessment. 2-Thiobarbituric acid reactive substance (TBARS) and volatile basic nitrogen (VBN) contents were measured as stability indicators. Additionally, total phenolic contents (TPC), total flavonoid contents (TFC), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were evaluated. The HU, egg grade, albumen height, and yolk color of T3 were significantly higher than those of CON (p<0.05). No significant differences in eggshell thickness and eggshell breaking strength are observed among the groups. The weight loss of T3 was significantly lower than that of the other groups during storage (p<0.05). The application of lotus leaf hot water extracts also significantly reduced TBARS and VBN (p<0.05). The TPC, TFC, and DPPH radical scavenging activity of T3 were significantly higher than those of the other groups (p<0.05). These results suggest that lotus leaf hot water extracts may be useful as a natural ingredient for improving the quality and stability of eggs during storage.

• Journal of Ecology and Environment
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• 제29권6호
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• pp.581-584
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• 2006

냉온대림의 주요 구성종으로 산지에도 분포하며 정원수로도 식재되고 있는 느티나무와 자작나무 그리고 미국에서 도입되어 조경수로 많이 활용되는 백합나무에서 내건성과 관련한 식물의 조직 수분 특성을 비교하였다. 한계원형질분리가 일어나는 점에서의 삼투포텐셜은 느티나무에서 -2.54 MPa로 가장 낮은 값을 나타내었으며, 백합나무에서 -2.03 MPa로 가장 높은 값을 나타내었다. 잎의 수분포텐셜 변화에 대한 압력 포텐셜의 변화에서도 느티나무가 가장 논은 압력포텐셜을 유지하였다. 세포의 자유수 함량 저하에 대한 압력포텐셜 변화 곡선은 전체적으로는 비슷한 패턴의 곡선을 나타내었지만 세포의 자유수 감소 시, 느티나무와 자작나무는 백합나무보다 높은 압력포텐셜을 유지하였다. 따라서 이들 세 종 중에서는 백합나무가 내건성이 가장 낮았으며, 느티나무는 다른 두 종에 비해 내건성이 가장 강하였다.

• 공업화학
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• 제5권1호
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• pp.63-73
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• 1994

n-Tetradecyldimethylbenzylammonium chloride(TDAC)와 n-tetradecyltrimethylammonium methyl sulfate (TTAM)를 합성하고 각각에 물을 가하여 감량촉진제 용액 TDACW와 TTAMW를 각각 제조하였다. 제조된 TDACW와 TTAMW 각각을 NaOH와 병용하여 PET섬유를 감량가공처리한 결과, 감량률은 TDACW가 TTAMW보다 훨씬 높게 나타났으며, 적정 처리농도는 약 $8g/{\ell}$, 처리시간은 60~90분 및 처리액량비는 1:40~1:50이었다. 밀도와 결정화도는 감량률이 증가할수록 상승하였고, 인장강도는 역으로 감량률이 증가될수록 저하되었다. 또한 감량촉진제와 PET섬유와의 반응메카니즘을 고찰하여 감량촉진제가 촉매로서 작용함을 밝혔으며, SEM으로 감량가공된 PET섬유의 표면형태를 관찰하였다.

• 한국자동차공학회논문집
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• 제6권6호
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• pp.113-131
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• 1998

The objective of the present study is to investigate the characteristics of the dividing flow in the laminar flow region. Using glycerine water solution(wt43%) for Newtonian fluid and the polymer of viscoelastic fluid(500wppm) for non-Newtonian fluid, this research investigates the flow state of the dividing tube in steady laminar flow region of the two dimensional dividing tube by measuring the effect of Reynolds number, dividing angle, and the flow rate ratio on the loss coefficient. In T- and Y-type tubes, the loss coefficients of the Newtonian fluid decreases in constant rate when the Reynolds number is below 100. The effect of the flow rate ratio on the loss coefficients is negligible. But when the Reynolds number is over 100, the loss coefficient with various flow rate ratios approach an asymptotic value. The loss coefficient of the non-Newtonian fluid for different the Reynolds number shows the similar tendency of the Newtonian fluid. And when the Reynolds number is over 300, the loss coefficient is approximately 1.03 regardless of flow rate ratio or the dividing angle. The aspect ratio does hardly influence the reattachment length and the loss coefficient of both Newtonian and non Newtonian fluid. The loss coefficient decreases as the Reynolds number increases. The loss coefficient of Newtonian fluid is larger than that of non-Newtonian fluid.

• Tribology and Lubricants
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• 제27권5호
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• pp.275-280
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• 2011

Automotive wheel bearing grease helps to reduce stresses and prevent wear of wheel bearings. But it is easily contaminated by water and other contaminants. In this study, we investigated the property change of automotive wheel bearing grease under water contamination. The result showed that some properties such as dropping point, work penetration and oxidation stability were not influenced by water content. However, most of properties such as work stability, water washout characteristics, leakage tendency, oil separation, evaporation loss and rust protection became worse after water was added. This is thought that added water makes the interaction weak between thickener and base oil of grease.

• 한국염색가공학회지
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• 제13권2호
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• pp.42-42
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• 2001

Following the prior studs regarding that 1.0g of cotton fabric cound be dyed uniformly with a reactive dye in the solvent mixture of 2㎖ of water and 23㎖ of dichloromethane, silk fabric was dyed with C. I. Reactive Blue 203 in the water/dichloromethane two-phase immiscible solvent media. In order to minimize dye loss due to its hydrolysis, the reactive dyeing was carried out in dichloromethane containing a small amount of water. With only 3㎖ of water in 22㎖ of dichloromethane, 1.0g of silk fabric could be dyed perfectly. The uptake ratio was increased greatly, compared with that of normal reactive dyeing in a water medium. It would seem that the one of hydrophobic solvents, dichloromethane, can assist the even dyeing as it disperses a small amount of dye-dissolved water phase and conveys this water phase to the fabric entirely and uniformly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.270-272
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• 2004

At the water supply field, high voltage induction motor is main facility of a load equipment. The motor is often out of order and its noise, generated heat, loss etc occurred occasionally. especially, transmission motor for flux control generates an amount of the harmonics then have a bad influence upon the electric power system. In this study, to analyze the total harmonics distortion of the water supply field receiving high voltage, the harmonics measured and analyzed using the PQA(Power quality Analyzer) according to the electric power system and electrical load and the reduction method presented.

• 원예과학기술지
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• 제18권5호
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• pp.612-620
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• 2000

본 연구는 토양습윤제를 개발하기 위해 비이온계 계면활성제인 polyoxyethylene octylphenyl ether[$C_8H_{17}O(C_2H_4O)_{10}H$, POE]를 주 계면활성제로, polyoxyethylene+polypropyleneoxide tridecylether(1:1, w/w, CM-1), polyoxyethylene+polypropyleneoxide tridecylether+propyleneglycol monomethylether(1:1:2, w/w/w, CM-2) 및 glycerin+ditridecyl phthalate(1:1, w/w, CM-3)등 3종류의 부 계면활성제, 그리고 질석과 비석을 증량제로 조합하여 상토 내 농도변화, 초기습윤화에 미치는 영향 및 상토의 물리적 특성에 미치는 영향 등을 조사하였다. 비석이나 질석이 증량제로 이용되고 POE와 CM-1, 2 또는 3을 조합한 경우 초기용출량이 많았으며 6회 이후 급격히 감소하여 불안정한 용출곡선을 보였다. POE+CM-1, 2 또는 3이 상토의 초기습윤화에 미치는 영향에서 AquaGro가 혼합된 처리가 다른 모든 처리보다 초기 18시간 동안의 수분 보유량이 많았으나 처리간 차이가 뚜렷하지 않았으며, 84시간 이후에는 POE+CM-2 처리에서 가장 많은 수분을 보유하였고 무처리구를 제외한 모든 토양습윤제 혼합처리구간의 차이는 뚜렷하지 않았다. 증발에 의한 상토의 수분상실에서 비석이 증량제로 이용된 경우 POE+CM-3이 혼합된 상토의 증발속도가 가장 빨랐고 POE+CM-2, AquaGro, 무처리구, 그리고 POE+CM-1의 순으로 느려지는 경향이었다. 그러나 질석이 증량제로 이용된 경우 POE+CM-1의 증발속도가 다른 처리들 보다 월등히 빨라 수분상실량이 많았으며, POE+CM-3, AquaGro, 무처리구 그리고 POE+CM-2의 순으로 느려지는 경향이었다. 단위시간당 상토안으로 침투되는 수분량에서 비석이 증량제로 이용된 경우 POE+CM-1, POE+CM-3, AquaGro, POE+CM-2 및 무처리구의 순으로 단위시간당 침투되는 수분량이 적어지는 경향이었다. 질석이 증량제로 이용된 경우 POE+CM-3, AquaGro, POE+CM-1, POE+CM-2 및 무처리구의 순으로 단위시간당 침투되는 수분량이 적어지는 경향이었다.

• 디지털융복합연구
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• 제6권4호
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• pp.53-61
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• 2008

Organizations can experience serious financial and/or reputational losses if business activities are disrupted by an incident of information systems under the current business environment. The loss includes the intangible decline in brand image, customer separation, and the tangible loss such as decrease in business profits. Thus, it is necessary to take proactive initiatives by managing many kinds of risks an organization may have. Therefore, the enterprise risk management has been received a special attention by some advanced private companies, but not many public organizations. This paper describes an approach and some issues when the enterprise risk management was introduced in a domestic public organization.