• 한국농공학회논문집
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• 제48권7호
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• pp.73-86
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• 2006

Concentrated poultry production in the State of Alabama, U.S.A. results in excessive poultry litter. Application of poultry litter to pastures and row crops serves as a cheap alternative to commercial fertilizer. However, over the years, poultry litter application to perennial forage crops in the Appalachian Plateau region of North Alabama has resulted in phosphorus (P) buildup in soils. Phosphorus index (P-index) and comprehensive nutrient management plans (CNMP) are often used as a best management practice (BMP) for proper land application of litter. Because nutrient management planning is often not done for small animal feeding operations (AFOs), and also because, in case of excess litter, litter transportation infrastructure has not been developed, over application of poultry litter to near by area is a common practice. To alleviate this problem, optimal poultry litter management and transportation infrastructure needs to be developed. This paper presents a methodology to optimize poultry litter application and transportation through efficient nutrient management planning and transportation network analysis. The goal was accomplished through implementation of three important modules, a P-Index module, a CNMP module, and a transportation network analysis module within ArcGIS, a Geographic Information System (GIS). The CNMP and P-Index modules assist with land application of poultry litter at a rate that is protective of water quality, while the transportation network analysis module helps transport excess litter to areas requiring litter in the Appalachian Plateau and Black Belt (a nutrient-deficient area) regions. Once fully developed and implemented, such a system will help alleviate water quality problems in the Appalachian Plateau region and poor soil fertility problems in the Black Belt region by optimizing land application and transportation. The utility of the methodology is illustrated through a hypothetical case study.

• 상하수도학회지
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• 제33권3호
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• pp.215-224
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• 2019

Recent focus on wastewater treatment includes energy-saving and renewable energy generation for energy-independence of water infrastructures. Aeration and pumping in biological wastewater removal processes account for nearly 30-60% of the total electricity cost in real wastewater treatment plants. In this study, the performance and microbial characteristics were investigated in sequencing batch reactor under typical oxygen and oxygen limited condition. Under typical DO ($7.55{\pm}0.99mg/L$) and low DO ($0.23{\pm}0.08mg/L$) conditions, COD removal was stable over 91 % during SBR operation. Ammonia removal efficiency was reduced from 95.6 % to 89.2 % when DO concentration was dropped sharply. Phosphorus removal efficiency also reached 77% at oxygen-limited condition. The results indicated that removal efficiency both ammonia and phosphorus was influenced by DO condition. Microbial analysis revealed that Proteobacteria and Bacteroidetes at phylum level was dominant in typical DO and low DO conditions and DO concentration did not much affect phylum distribution. Population decrease of genera of nitrifying bacteria(Dokdonella) and Dechloromonas spp. affect removal efficiency of nitrogen and phosphorus at low DO condition.

• 융합정보논문지
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• 제12권3호
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• pp.85-107
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• 2022

본 연구는 수상 운송업이 전체 산업들과의 관계 속에서 경제 전반에 미치는 유발 효과 및 네트워크 연결성과 네트워크 시각화 분석을 시행하는 것이다. 이를 위하여 산업연관분석과 단위구조행렬을 활용하여 수상 운송업의 각종 유발계수를 분석하며, 단위구조행렬과 역행렬함수를 작성하고 Ucinet 6을 이용하여 네트워크 연결성과 NetDraw를 활용하는 네트워크 시각화 분석을 시행한다. 연구결과 수상 운송업의 각종 유발계수로서 투입계수, 생산유발계수, 부가가치유발계수, 산업간 연쇄효과의 분석 결과를 제시 하였으며, 네트워크 연결성으로서 연결중앙성, 인접중앙성, 사이중앙성 및 네트워크 시각화 분석의 내용을 제시하였다. 본 연구를 통하여 수상 운송업의 현재 위치와 현황 및 전체 산업들과의 관계를 확인하였으며 어떠한 산업들과 전략적 관계를 가져야 하는가를 제시하였다. 향후에는 2000년대 이후 발간된 산업연관분석을 활용하여 각종 유발 효과 및 연결성(중앙성), 네트워크 시각화 분석의 변동 현황과 추이에 대한 사항을 추가로 분석하는 것이 필요하다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.382-387
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• 2012

Water balance has a significant impact on the overall fuel cell system performance. Proper water management should provide an adequate membrane hydration and avoidance of water flooding in the catalyst layer and gas diffusion layer. Considering the important of advanced water management in PEM fuel cell, this study proposes a simple one dimensional water transportation model of PEM fuel cell for use in a dynamic condition. The model has been created by assumption that the output is the water liquid saturation difference. The liquid saturation change is the total difference between the additional water and the removal water on the system. The water addition is obtained from fuel cell reaction and the electro osmotic drag. The water removal is obtained from capillary transport and evaporation process. The result shows that the capillary water transport of low temperature fuel cell is high because the evaporation rate is low.

• 한국수산과학회지
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• 제33권2호
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• pp.119-123
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• 2000

은연어가 운반과정 중에 어느 정도 스트레스를 받는지 조사하기 위하여 어류를 각각 담수와 염수 ($5{\%{\circ}}$)를 채운 수조차에 싫고 10 시간 운반하였다. 운반하기 전후에 혈청 중의 1차 스트레스 지표 물질인 코티졸을 비롯하여 2차 지표물질인 GLC, LAC, TG, CHOL, 전해질 ($Na^+, Cl^-$), 효소 (ALT, AST, LDH) 활성을 측정하여 두 운반구 간의 차이를 비교하였다. 그 결과, 운반작업은 은연어에게 상당한 스트레스를 주는 것으로 확인되었으나, 운반방법에 따라서는 스트레스 반응에 차이가 있었다. 즉, 담수운반구에 비해 염수운반구는 코티졸, GLC, LAC, TG, CHOL, AST 및 ALT가 유의적인 차이를 보이며 낮은 수준이었다. 이것으로 은연어의 운반시에는 담수보다 염수를 사용하는 것이 스트레스를 줄일 수 있다는 것을 알 수 있었다.

• 한국물환경학회지
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• 제28권2호
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• pp.300-304
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• 2012

It has a limitation to satisfy the phosphorus effluent criteria of 0.2 mg/L which will be reinforced from 2012 with the Biological Nutrient Removal (BNR) process. The chemical coagulation process has been operated in parallel with the biological treatment process for advanced treatment of phosphorous in the developed countries including Europe. However, the coagulation process has some disadvantages such as the desired goal may not be achieved without injecting the optimum dosage of the coagulant. This study developed the automatic control system to inject the optimum dosage of phosphorous coagulant into the coagulation process. The adopted coagulant was 10% Poly Aluminum Chloride (PAC) in this study. The automatic control system developed in this study was adopted for the treatment of the phosphorus from the effluent in SBR process. The automatic control system was composed of the data receiving part, the optimum coagulant dosage control part and the data transmit part. The result of the phosphorous advanced treatment of the SBR effluent using the automatic control system showed the removing efficiency over 95% consistently with the phosphorous concentration under 0.02 ~ 0.15 mg/L. The reproducibility analysis for checking the safety of automatic control system showed more than 95% correlation.

• 한국식품영양학회지
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• 제30권4호
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• pp.847-851
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• 2017

This purpose of this study was to investigate cooking characteristics of noodles prepared by adding 0, 2, 4 or 6 percent of Capsosiphon fulvescens to wheat flour containing konjac powder. Water binding capacity was significantly increased with increasing amounts of Capsosiphon fulvescens. Weight and volume of cooked noodles increased significantly in proportion with the amount of Capsosiphon fulvescens. Turbidity of the soup after cooking also increased with the addition of Capsosiphon fulvescens. Brightness(L) and redness(a) were decreased with addition of Capsosiphon fulvescens. Yellowness(b) increased. The color value of cooked noodles was decreased compared with that of wet noodles. Sensory evaluation scores revealed that cooked noodles with 4 percent addition group were highest in terms of color, flavor and overall acceptability. This study validates that addition of Amorphophallus konjac and 4 percent Capsosiphon fulvescens may improve functionality and preference of noodles.

• 설비공학논문집
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• 제23권4호
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• pp.259-264
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• 2011

Gas hydrate is formed by physical binding between water molecule and gas such as methane, ethane, propane, or carbon dioxide, etc., which is captured in the cavities of water molecule under the specific temperature and pressure. $1\;m^3$ hydrate of pure methane can be decomposed to the methane gas of $172\;m^3$ and water of $0.8\;m^3$ at standard condition. If this characteristic of hydrate is reversely utilized, natural gas is fixed into water in the form of hydrate solid. Therefore, the hydrate is considered to be a great way to transport and store of natural gas in large quantity. Especially the transportation cost is known to be 18~25% less than the liquefied transportation. However, when methane gas hydrate is artificially formed, its reaction time may be too long and the gas consumption in water becomes relatively low, because the reaction rate between water and gas is low. Therefore, for the practical purpose in the application, the present investigation focuses on the rapid production of hydrates and the increment of the amount of captured gas by adding zeolite into pure water. The results show that when the zeolite of 0.01 wt% was added to distilled water, the amount of captured gas during the formation of methane hydrate was about 4.5 times higher than that in distilled water, and the methane hydrate formation time decreased at the same subcooling temperature.

• 한국유체기계학회 논문집
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• 제14권6호
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• pp.18-25
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• 2011

A boundary-layer pump with a single disk has been experimented to obtain its characteristic curve by changing the impeller of a centrifugal pump to a single disk. The primary objective to use of these types of pumps is to avoid hurting water life during transportation unnecessarily. The change of impeller should degrade the performance of pump, so we used the method to increase the roughness on the disk with sandpaper and mesh. The enhancement of shear force from the rotation of disk to the internal flow brought an augmentation of momentum transport, and the characteristics were far improved from the original single-disk pump without decreasing the survival rate of water life in the case of Pseudobagrus fulvidraco (bullhead fish). However, in the case of Artemia cyst (zooplankton), the survival rate was very degraded due to the micro scale smaller than turbulent eddy size. The result of this study could be used for the design of transportation and bio-filtering of water lying on a specific bandwidth of its scale of size.

• 한국농공학회지
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• 제39권2호
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• pp.74-85
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• 1997

This study aims at the development of a mathematical approach for the optimal water allocation in the river basin where available water is not in sufficient. Its optimal allocation model is determined from the comparison and analysis of mathematical programming techniques such as transportation programming and dynamic programming models at its optimal allocation models. The water allocation system used in this study is designed to be the optimal water allocation which can satisfy the water deficit in each district through inter-basin water transfer between Kumho river basin which is a tributary catchment of Nakdong river basin, and the adjacent Hyungsan river basin, Milyang river basin and Nakdong upstream river basin. A general rule of water allocation is obtained for each district in the basins as the result of analysis of the optimal water allocation in the water allocation system. Also a comparison of the developed models proves that there is no big difference between the models Therefore transportation programming model indicates most adequate to the complex water allocation system in terms of its characteristics It can be seen, however, that dynamic programming model shows water allocation effect which produces greater net benefit more or less.