• 한국작물학회지
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• 제46권2호
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• pp.78-83
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• 2001

Two rice cultivars of the japonica type, ozone-resistant Ilpumbyeo (IL) and ozone-susceptible Keu-mobyeo#l (KM) were exposed to ozone ($O_3$) at 0.15 ppm for 30 days. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) within a basic fertilizer status (N, P, K; 15, 12, 12 kg l0$a^{-1}$). There was little difference on plant height between ozone-treated and nontreated plants. The most significant ozone stress on tiller number was shown on the 30th day of ozone exposure. Slight recovery from ozone stress was noted on the 60th day. On the 30th day, tiller number was greatly decreased by 40.8% in IL and 64.6% in KM, whereas at a high nitrogen supply regime (2N), it was decreased by 21.4% in IL and 42.7% in KM as compared to the control not treated with ozone at basic fertilizer status. The inhibition of tiller production caused by ozone exposure was alleviated on the 60th day. In both cultivars, number of spikelets per plant and weight of 100 grains were affected little by the ozone treatment irrespective of nutrient regime. However, the number of panicles per plant and yield were reduced significantly. In both cultivars, yield of ozone-treated plants with 2N status was 12.4-16.1 % higher than that of the ozone-treated plants with basic nutrient status. A significant yield decrease of 47.8% and 33.4% was observed for IL and KM, respectively, in ozone-treated plants with higher potassium (2K) status.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.364-370
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• 1997

Four local cattle were ($145{\pm}9.7kg$) used in a $4{\times}4$ Latin square design to study the effect of different levels of rumen degradable protein (RDP) in straw based ration on purine derivatives excretion and microbial N supply in cattle. The four rations were formulated at the same amount of energy but varying RDP approximately 50 (U0), 75 (U1), 100 (U2) and 150 (U3) percent levels of RDP requirement for maintenance. They were fed ranged from 101 to 304 g RDP/d. Apparent digestibility of all nutrients increased significantly (p < 0.01) in cattle fed ration U2 than other rations. Rumen $NH_3-N$ concentration increased from 43 to 130 mg/l in response of RDP intake. Purine derivatives excretion increased significantly (p < 0.01) with incremental level of 203 g RDP/d (U2) intake and positively correlated (r=0.69, p < 0.01, n=16) with amount of RDP intake. The rates of rumen microbial N supply were 16.8, 27.2, 39.1 and 32.9 g/d for rations U0, U1, U2 and U3 respectively. Efficiency of microbial N supply (EMNS) per kg of DOMR were 19.0, 25.3, 33.0, and 28.6 g and per MJ of ME. Intake were 0.62, 1.00, 1.44 and 1.21 g for U0, U1, U2 and U3 respectively and highest results were obtained in cattle fed U2 ration. Results of this study suggest that PD excretion and EMNS were increased as incremental level of RDP intake (U2) in local cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.378-387
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• 2009

To investigate the effects of sago palm pith (SPP) substitution of corn in the diets on intake, digestibility, rumen fermentation characteristics, nitrogen balance and microbial N Supply, five ruminally fistulated Southern indigenous cattle (mean initial BW = 226${\pm}$5 kg) were randomly assigned to a 5${\times}$5 Latin Square Design to receive five diets, $T_1$ = concentrate with 0% SPP, $T_2$ = 25% SPP, $T_3$ = 50% SPP, $T_4$ = 75% SPP and $T_5$ = 100% SPP, of dietary dry matter, respectively. Plicatulum hay (PH) was offered ad libitum as the roughage. A metabolism trial lasted for 21 days during which liveweight changes and feed intakes were measured. Based on this experiment, there were no significant differences (p>0.05) among treatments groups regarding total DM intake (OMI, NDFI and ADFI) and digestion coefficients of nutrients (DM, OM, CP, NDF and ADF), while total DM intake (% BW) was significantly (p<0.05) higher as higher levels of SPP were incorporated into diets. Rumen parameters (ruminal temperature, pH, glucose, packed cell volume, volatile fatty acid and rumen microorganism populations) were similar among treatments (p>0.05), whereas $NH_3-N$, blood urea nitrogen and molar proportion of propionate concentrations were significantly (p<0.05) higher as higher levels of SPP were incorporated into diets. The amount of N absorption, N retention and microbial protein synthesis were similar among treatments. These results indicate that SPP can be included in diets for Southern indigenous cattle to supply up to 100% of supplemental corn when fed with PH without negative impact on animal performance and it was a good approach in exploiting the use of local feed resources for beef cattle production.

• 농업과학연구
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• 제50권2호
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• pp.181-192
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• 2023

Appropriate fertilization methods are required according to species to supply necessary nutrients to plants and prevent soil environmental contamination in nurseries. In this study, the effects of nitrogen and phosphorus fertilization on the growth of Liriodendron tulipifera and soil characteristics were investigated. After 16 fertilization treatments (4 levels of nitrogen × 4 levels of phosphorus) were applied to one-year-old L. tulipifera seedlings at the Yongmun Nursery Station of the Korea Forest Service, height, root collar diameter (RCD), biomass, leaf nutrients, and soil characteristics were investigated. The height increased as the amount of nitrogen and phosphorus fertilization increased, and the RCD was the highest in the ×2 treatment. Biomass growth was on average 40.0% higher for the treatment with high nitrogen fertilization compared to the low nitrogen treatment. The seedling quality index was the highest with nitrogen and phosphorus ×2 treatment. Leaf phosphorus and magnesium concentrations decreased when nitrogen fertilization was applied, and leaf potassium concentrations decreased as nitrogen fertilization increased. Soil pH and exchangeable potassium decreased as the amount of phosphorus application increased, and exchangeable magnesium decreased as the amount of nitrogen application increased and increased as the amount of phosphorus application increased. Considering the growth of L. tulipifera seedlings and changes in the soil characteristics at the nursery stage, twice the standard fertilization amount is the appropriate fertilization amount for nursery of the Yongmun Nursery Station. It is expected that this study will contribute to improving nursery soil fertilization management technology for healthy seedling production.

• 한국폐기물자원순환학회지
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• 제35권7호
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• pp.647-652
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• 2018

The emission of nitrogen oxides has a great environmental impact. It leads to Los Angeles type smog, and it recently has attracted attention as a source of ultrafine dust. The main sources of nitrogen oxides are internal combustion engines and industrial boilers. These emission sources are processes that are essential for human industrial activities, so the regulation of original use is impossible. Therefore, special control methods should be applied to reduce NOx emissions into the atmosphere. In this study, we investigated how the supply of ER and urea influences the removal of nitrogen oxides from SRF combustion boilers. Experimental results show that the removal efficiency of nitrogen oxides can be up to 80% under the conditions of ER 2.0 and a urea feed of 0.5 LPM.

• 생물환경조절학회지
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• 제6권2호
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• pp.97-102
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• 1997

소과종 수박의 고밀도 지주재배시 질소시비량을 260, 200, 140, 0kg/ha, 무비구로 하여 생육, 수량, 품질 및 무기양분 흡수에 미치는 영향을 조사한 결과는 다음과 같다. 생육특성은 질소시용구가 0kg 시용구와 무비구보다 초장, 엽면적, 생체중 및 건물중이 좋았고, 질소 시용구간에는 차이가 없었으며 엽수는 모든 처리구에서 차이가 없었다. 수량특성은 140kg/ha 시용구가 32,010kg/ha으로 가장 높았고, 착과율도 79%로 가장 높았다. 품질특성은 140kg/ha 시용구가 식미지수 3.9, 당도 12.5 $^{\circ}$Bx로 다른 처리구보다 좋았고, 무비구가 12.0 $^{\circ}$Bx로 처리구 중에서 가장 낮았다. 과피두께는 질소시비량이 증가할수록 두꺼웠다. 엽내 T-N의 함량은 질소시비량이 많았던 처리구일수록 증가폭이 컸으며, 모든 처리구에서 생육중기에 가장 많이 흡수되었다. 인산함량은 질소시비량에 따라서 큰 차이가 없었으며 칼슘함량은 질소시비량이 많을수록 증가하는 경향을 보였고, 마그네슘 함량은 칼슘과는 달리 질소시비량이 많을수록 생육후기에 낮았다.

• 한국자원식물학회지
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• 제35권2호
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• pp.192-200
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• 2022

본 연구에서는 부지화 잎의 무기양분 농도 측정 결과를 바탕으로 질소를 제외한 다른 무기양분의 함량을 통해서 잎의 질소 결핍 여부를 구분하는 머신러닝 모델을 개발하였다. 그러기 위해서 부지화의 질소결핍구와 대조구의 잎 샘플을 분석한 36개의 데이터를 부트스트랩핑 방법을 통해서 학습용 데이터셋 1,000 여 개로 증량시켰다. 이를 이용해 학습한 각 모델을 테스트한 결과, gradient boosting 모델이 가장 우수한 분류성능을 보여주었다. 본 모델을 이용해 질소함량을 직접적으로 분석할 수 없는 경우, 잎의 무기성분 함량에 기반하여 질소결핍 가능성 여부를 판단해 질소가 부족한 부지화 나무를 분별하고, 정확한 질소함량을 측정하게 유도하여 그에 기초한 적정 질소비료 시비를 가능케 하고자 하였다.

• 한국대기환경학회지
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• 제21권6호
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• pp.657-666
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• 2005

The objectives of this study were to investigate atmospheric dry deposition of inorganic nitrogen-containing compounds to waterbody. Target waterbody is Juam reservoir functioning as one of the major water supply sources in Chollanamdo. Nitrate and ammonium dry deposition fluxes were directly measured using dry deposition plate (DDP) covered with greased strips and a water surface sampler (WSS). The daytime average $NO_{3}^{-}\;and\;NH_{4}^{+}$ fluxes measured with DDP and WSS were $1.7\∼2.6$ times higher than those at nighttime. The seasonal average flux of $NH_{4}^{+}$ showed the highest value in summer. The daytime and nighttime average dry deposition fluxes of particulate phase Nitogen-containing Compounds ($1.13,\;0.80\;mg/m^{2}$ day) were much higher than those of gas phase compounds ($0.50,\;0.24\;mg/m^{2}$ day).

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.281-283
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• 2003

High temperature superconducting power cable requires forced flow cooling. Liquid nitrogen is circulated by a pump and cooled back by cooling system. Typical operating temperature range is expected to be between 65K and 80K. Subcooler heat exchanger uses saturated liquid nitrogen boiling on the shell side to subcool the circulating liquid nitrogen stream that cools the HTS cable. The paper describes performance tests of the cooling system. The test items are heat exchanging performance of subcooler. pressure drop between supply and return lines, heat transfer coefficient inside former, cable cryostat heat leak and simulation of electrical load of HTS cable.

• 한국토양비료학회지
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• 제29권3호
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• pp.282-287
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• 1996

시설재배지(施設栽培地)에 적합한 질소공급력(窒素供給力) 지표(指標)를 알기 위하여 토양유기물(土壤有機物), 총질소(總窒素), 6N HCl가용질소 및 2M KCl, 0.01M $CaCl_2$, 0.01M $NaHCO_3$ 침출질소(浸出窒素)와 배추의 수량(收量) 및 질소흡수량(窒素吸收量)과의 관계를 비교(比較) 검토(檢討)한 결과(結果)는 다음과 같다. 배추수량(收量)과 침출방법(浸出方法)에 따른 질소함량(窒素含量)과의 상관(相關)에서 2M KCl침출(浸出) 총(總) 무기태(無機態) 질소(窒素)(r= 0.789)와 질산태질소(窒酸態窒素) (r=0.765)가 가장 높았으며, 그 다음으로는 토양유기물(土壤有機物) > T-N > 0.01M $NaHCO_3$ 침출질소(浸出窒素) > 0.01M $CaCl_2$ 침출질소(浸出窒素) > 2M KCl침출(浸出) $NH{_4}^+-N$ > 6N HCl가용질소순(可溶窒素順)으로 2M KCl침출(浸出) 총무기웅질소량(總無機熊窒素量)과 질산태질소(窒酸態窒素)가 시설재배지(施設栽培地)의 질소시비추천(窒素施肥推薦)을 위한 우수(優秀)한 지표성분(指標成分)이었다. 토양(土壤) 중 질산웅질소량(窒酸熊窒素量)과 시비질소량(施肥窒素量)의 합(合)과 배추의 수량(收量) 및 질소흡수량(窒素吸收量)과는 고도(高度)의 유의성(有意性)있는 정(正)의 상관관계(相關關係)가 있으며, 토양의 질소함량과 시비효율(施肥效率)과는 부(負)의 상관관계(相關關係)가 있었다. 토양질소침출방법별(土壤窒素浸出方法別) 질소함량간(窒素含量間)의 상관관계(相關關係)에서 $NO{_3}^-+NH{_4}^+-N$는 0.01M $NaHCO_3$와 0.01M $CaCl_2$ 침출성질소(浸出性窒素), OM은 T-N와 6N HCl가용성(可溶性) 질소(窒素), T-N는 6N HCl가용성질소(可溶性窒素) 및 0.01M $CaCl_2$ 침출질소(浸出窒素)와 높은 정(正)의 상관관계(相關關係)를 나타 내었다.