• 한국초전도ㆍ저온공학회논문지
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• 제20권2호
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• pp.6-10
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• 2018

Removal of iron oxide scale from feed-water in thermal power plant can improve power generation efficiency. We have proposed a novel scale removal system utilizing High Gradient Magnetic Separation (HGMS). This system can be applied to high temperature and pressure area. We have conducted the lab-scale model experiments using ${\varphi}50mm$ filters and it demonstrated high removal efficiency in HGMS, but scale-up of the system is required toward practical use. In this study, we conducted a large scale mock-up HGMS experiment. We used the superconducting solenoidal magnet with ${\varphi}400mm$ bore and demonstrated that our HGMS system can achieve sufficient scale removal capacity that is required to introduce into both off-line and on-line system.

• Journal of Advanced Marine Engineering and Technology
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• 제36권6호
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• pp.768-773
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• 2012

유기 랭킨사이클의 증발기 2차 유체로서 화력발전소에서 버려지는 $35^{\circ}C$의 온배수를 이용하는 경우와 $25^{\circ}C$의 해양 표층수를 이용하는 경우의 사이클 특성을 서로 비교한 후, 유기 랭킨사이클에 화력발전소에서 버려지는 온배수를 유기 랭킨 사이클에 적용 가능한지를 확인 하였다. 본 연구에서 고려된 작동변수는 과열도, 과냉각도, 터빈효율, 펌프효율 등이다. 주요 결과를 요약하면 다음과 같다. 화력발전소에 배출되는 $35^{\circ}C$의 온배수를 적용한 유기 랭킨사이클의 효율이 $25^{\circ}C$의 표층수를 적용한 유기 랭킨사이클에 비해 87% 이상 높게 나타났다. 따라서 화력발전소의 온배수를 유기 랭킨사이클에 적용할 수 있음을 확인할 수 있었다.

• 한국산업융합학회 논문집
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• 제24권3호
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• pp.333-341
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• 2021

Irrigation scheduling is a water management strategy of applying the proper amount of water in a plant's root zone at the right time to maximize profit. We conducted an experimental evaluation of the response of soybean, sorghum, and sesame to an irrigation scheduling scheme. The soil water contents were adjusted in the root zone between 20% and 28% to reflect changes in crop water consumption. The other ones fixed at 25% during the whole growing season were compared to evaluate the effectiveness of irrigation scheduling. Surface drip irrigation (SDI) were employed as an irrigation method. For all three crops, the evapotranspiration (ET) was the greatest at flowering stage (6.93 mm), followed by vegetative growth stage (5.00 mm) and maturity stage (2.53 mm). The irrigation amount was significantly reduced by 21.8% (soybean), 22.2% (sorghum), and 16.1% (sesame), respectively, compared with the ones at constant soil water content treatment. Their water use efficiency (WUE) were also much higher than the controls: 2.65-fold increase at soybean, 1.82-fold increase at sorghum, and 1.47-fold increase at sesame. These results showed that an effective irrigation scheduling on upland crops (soybean, sorghum, sesame) could increase crop yield while minimizing water use.

• Advances in nano research
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• 제15권5호
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• pp.441-449
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• 2023

Heavy metals, widely present in the environment, have become significant pollutants due to their excessive use in industries and technology. Their non-degradable nature poses a persistent environmental problem, leading to potential acute or chronic poisoning from prolonged exposure. Recent research has focused on separating heavy metals, particularly from industrial and mining sources. Industries such as metal plating, mining operations, tanning, wood and chipboard production, industrial paint and textile manufacturing, as well as oil refining, are major contributors of heavy metals in water sources. Therefore, removing heavy metals from water is crucial, especially for safe water supply in swimming and water sports. Iron oxide nanoparticles have proven to be highly effective adsorbents for water contaminants, and efforts have been made to enhance their efficiency and absorption capabilities through surface modifications. Nanoparticles synthesized using plant extracts can effectively bind with heavy metal ions by modifying the nanoparticle surface with plant components, thereby increasing the efficiency of heavy metal removal. This study focuses on removing lead from industrial wastewater using environmentally friendly, cost-effective iron nanoparticles synthesized with Genovese basil extract. The synthesis of nanoparticles is confirmed through analysis using Transmission Electron Microscope (TEM) and X-ray diffraction, validating their spherical shape and nanometer-scale dimensions. The method used in this study has a low detection limit of 0.031 ppm for measuring lead concentration, making it suitable for ensuring water safety in swimming and water sports.

• 생물환경조절학회지
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• 제31권4호
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• pp.300-310
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• 2022

본 실험은 펄라이트 수경재배에서 급액량이 토마토(Solanum lycopersicum L.)의 생육과 수량에 미치는 영향을 조사하기 위해 수행되었다. 급액 처리는 대조구인 I₀와 대조구보다 급액량이 각 25%, 50% 많은 I₂₅와 I₅₀로 세수준 처리하였다. 처리기간 중 대조구 I₀ 처리구는 배액이 없었다. 조사항목으로 토마토 생육특성, 수량 및 수분이용효율을 측정하였다 토마토의 초장, 엽장 및 엽폭이. I₀ 처리 가장 짧았고 I₂₅와 I₅₀ 처리에서는 통계적으로 차이가 없었다. 처리 후 111일, 132일 및 143일째에 측정한 토마토 과실의 당도, 산도 및 건물율은 관수량이 가장 적은 I₀가 관수량이 많은 I₂₅와 I₅₀ 보다 높았다. 그러나 처리 후 111일과 132일째 과실 내 수분함량은 I₀ 처리에서 가장 낮았다. 대과(>180g)의 수는 I₂₅에서 유의하게 더 많았으나 총 수확과 수는 처리 간 유의한 차이가 없었다. 과실의 평균 과중(g·plant^-1)과 총 수확량(g·plant^-1)은 I₀ 처리된 토마토에서 가장 낮았다. 수분 소비량은 처리 간 유의한 차이가 없었으나 수분이용효율은 I₀ 처리에서 가장 낮았다. 주성분 분석 결과 과실의 당도와 산도는 양의 상관관계가 있는 것으로 나타났다. 본 실험에서 토마토 생육, 과실 특성 및 수분이용효율을 토대로 얻은 결과는 I₂₅가 토마토 펄라이트 수경재배에서 다른 처리 보다 적절한 급액량임을 보여준다.

• 한국초지조사료학회지
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• 제41권4호
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• pp.280-286
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• 2021

The objective of this study was to prove the effect of pig slurry application with charcoal on nitrogen use efficiency (NUE), feed value and ammonia (NH₃) emission from maize forage. The four treatments were applied: 1) non-pig slurry (only water as a control), 2) only pig slurry application (PS), 3) pig slurry application with large particle charcoal (LC), 4) pig slurry application with small particle charcoal (SC). The pig slurry was applied at a rate of 150 kg N ha^-1, and the charcoal was applied at a rate of 300 kg ha-1 regardless of the size. To determine the feed value of maize, crude protein, dry matter intake, digestible dry matter, total digestible nutrient, and relative feed value were investigated. All feed value was increased by charcoal treatment compared to water and PS treatment. Also, the NUE for plant N was significantly higher in charcoal treatments (LC and SC) compared to PS treatment. On the other hand, there is no significant difference for feed value and NUE between LC and SC. The NH₃ emission was significantly reduced 15.2% and 27.9% by LC and SC, respectively, compared to PS. Especially, SC significantly decreased NH₃ emission by 15% compared to LC. The present study clearly showed that charcoal application exhibited positive potential in nitrogen use efficiency, feed value and reducing N losses through NH₃ emission.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.161-164
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• 2008

For the development of solar thermal power tower plant from the early 80' to today, various kinds of receiver have been tested and evaluated. Most of 1st generation receiver used water/steam as a working fluid to operate steam turbine and now the first commercial solar power tower PS-10 also makes saturated steam. However, to increase thermal efficiency of storage system and to obtain practical use of solar energy, molten salt system have been used from THEMIS project in France at 1984. The Solar Tres plant of 17 MWe power generation will be constructed in Spain and have plan to operate 24 hours in summer. The air volumetric receiver system can be integrated with combined cycle of gas turbine and HRSG and also with steam turbine easily. Therefore, related researches to develop higher efficient solar power tower plant and to operate with stable are widely performed in the world.

• 상하수도학회지
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• 제21권6호
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• pp.727-735
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• 2007

The use of water by cities is increasing owing to industrialization, the concentration of population, and the enhancement of the standard of living. Accordingly, the amount of waste water is also increasing, and the degree of pollution of the water system is rising. In order to solve this problem, it is necessary to remove organisms and suspended particles as well as the products of eutrophication such as nitrates and phosphates. This study developed a high-end treatment engineering solution with maximum efficiency and lower costs by researching and developing a advanced treatment engineering solution with the use of Biosorption. As a result, the study conducted a test with a $50m^3/day$ Pilot Scale Plant by developing treatment engineering so that only the secondary treatment satisfies the standard of water quality and which provided optimal treatment efficiency along with convenient maintenance and management. The removal of organisms, which has to be pursued first for realizing nitrification during the test period, was made in such a way that there would be no oxidation by microorganisms in the reactor while preparing oxygen as an inhibitor for the growth of microorganism in the course of moving toward the primary settling pond. The study introduced microorganisms in the endogeneous respiration stage to perform adhesion, absorption, and filtering by bringing them into contact with the inflowing water with the use of a sludge returning from the secondary settling pond. Also a test was conducted to determine how effective the microorganisms are as an inner source of carbon. The HRT(Hydraulic Retention Time) in the nitrification tank (aerobic tank) could be reduced to two hours or below, and the stable treatment efficiency of the process using the organisms absorbed in the NAR reactor as a source of carbon could be proven. Also, given that the anaerobic condition of the pre-treatment tank becomes basic in the area of phosphate discharge, it was found that there was excellent efficiency for the removal of phosphate when the pre-treatment tank induced the discharge of phosphate and the polishing reactor induced the uptake of phosphate. The removal efficiency was shown to be about 94.4% for $BOD_5$. 90.7% for $COD_{Cr}$ 84.3% for $COD_{Mn}$, 96.0% for SS, 77.3% for TN, and 96.0% for TP.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.296-300
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• 2005

Human-induced soil salinity is becoming a major threat to agriculture across the world. This salinisation occurs in both irrigated and rain-fed agricultural zones with the highest proportions in the arid and semi-arid environments. Livestock can play an important role in the management and rehabilitation of this land. There are a range of plants that grow in saline soils and these have been used as animal feed. In many situations, animal production has been poor as a result of low edible biomass production, low nutritive value, depressed appetite, or a reduction in efficiency of energy use. Feeding systems are proposed that maximise the feeding value of plants growing on saline land and integrate their use with other feed resources available within mixed livestock and crop farming systems. Salt-tolerant pastures, particularly the chenopod shrubs, have moderate digestible energy and high crude protein. For this reason they represent a good supplement for poor quality pastures and crop residues. The use of salt-tolerant pasture systems not only provides feed for livestock but also may act as a bio-drain to lower saline water tables and improve the soil for growth of alternative less salt tolerant plants. In the longer term there are opportunities to identify and select more appropriate plants and animals for saline agriculture.

• 생물환경조절학회지
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• 제18권4호
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• pp.408-412
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• 2009

펄라이트 자루재배시 일중 관수마감시각을 달리함으로써 최적 생장을 유지하면서도 용수이용효율(WUE)과 비료이용효율(FUE)을 높이기 위해 실험을 실시하였다. 관수마감시각에 따라 일몰 1시간 전부터 4시간 전까지 4단계로 나누어 처리한 결과, 배지 내 수분함량은 마감시각이 늦을수록 많은 경향을 나타냈다. 최종 생육은 일몰 4시간 전 처리구에서 약간 낮은 경향을 보이기는 했으나, 통계적 유의차는 보이지 않았다. 상품수량은 일몰 1시간 전 및 2시간 전에서 가장 많았고, 4시간전에서 가장 적었다. 관수마감시각 처리별 128일 동안의 급액량을 조사한 결과, WUE와 FUE는 일몰마감 1시간 전 처리구에서 가장 낮았고, 3시간 전 처리구에서 가장 높았다. 식물생육, 수확량 및 WUE와 FUE 등의 면에서 일몰 4시간 전에 관수를 중단하는 것은 바람직하지 않으며, 2~3시간 전에 마감하는 것이 좋을 것으로 사료된다.