• 한국지구과학회지
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• 제44권4호
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• pp.291-306
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• 2023

Shallow groundwater in rural areas is primarily polluted by agricultural activities. Nitrate-nitrogen is an indicator of artificial pollution. In this study, the hydrochemical characteristics and nitrate-nitrogen pollution of shallow groundwater were examined in two agricultural villages (Hyogyo-ri and Sinan-ri) in Chungcheongnam-do Province, Korea. Physicochemical quality analysis of shallow groundwater and stream water in the field, and chemical analysis in the laboratory were conducted from July 2020 to October 2021. In Hygyo-ri and Sinan-ri villages, shallow groundwater mainly belonged to the Ca-Cl, Ca-H CO₃, Na-HCO₃, and Na-Cl types, whereas stream water predominantly belonged to the Ca-HCO₃ type. The nitrate-nitrogen concentration in shallow groundwater varied depending on the season, displaying an increased concentration of nitrate-nitrogen in the dry season compared to the rainy season. Stream water may be influenced by runoff into villages from the surrounding area, although both shallow groundwater and stream water are affected by artificial pollution. In addition, the nitrate-nitrogen concentration in stream water was lower than that in shallow groundwater.

• Asian-Australasian Journal of Animal Sciences
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• 제11권6호
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• pp.718-724
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• 1998

Twelve gilts were used to investigate the effect of lysine to protein ratio (5.2 g lysine/100 g CP vs. 6.7 g lysine/100 g CP) in practical diets on nitrogen retention and the efficiency of utilization in growing pigs. Treatments involved 2 levels of dietary lysine (5.2 or 6.7 g/100 g CP) and 3 levels of dietary crude protein (11, 14 and 17% in diet). Nitrogen retention was greatest when pigs were fed the control diet containing 17% protein. Nitrogen retention progressively increased as dietary protein increased (p < 0.01), but it was not affected by lysine concentration (g/100 g CP). Apparent biological value (ABV, nitrogen retained/apparently digestible nitrogen) was estimated to be ~50% at the maximum nitrogen retention. ABV was not affected by lysine concentration, but declined (p < 0.05) as the dietary protein level increased. The efficiency of intake N used for maximum nitrogen retention was approximately 44%. One gram of lysine supported approximately 9 to 10 g apparent protein accretion (nitrogen retention ${\times}$ 6.25/lysine intake) in pigs fed control diets. The efficiency of lysine utilization for protein accretion was lower in pigs fed high-lysine diets (6.7 g lysine/l00 g CP) so that 1 g of lysine accounted for 7 to 8 g of protein accretion in these pigs (p < 0.01). The lysine required to support maximum nitrogen retention in pigs fed high-lysine diets was higher than that in pigs fed control diets, which suggests that lysine was over-fortified relative to crude protein, since practical diets can not be formulated without excess of some amino acids. In summary the concentration of 5.2 g total lysine/100 g CP in diet is more appropriate for corn-soybean diets than the commonly suggested the content of 6.7 g total lysine/100 g CP.

• 한국재난정보학회 논문집
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• 제16권3호
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• pp.542-549
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• 2020

연구목적: 액비의 발효과정에서 생산된 질산성질소는 물의 오염지표로써 본 연구에서는 액비가 살포된 4개의 연구지역을 선정하고, 질산성질소의 오염 농도를 추정할 수 있는 모델을 제작하고자 하였다. 연구방법:현장촬영에 앞서 액비의 비율을 0%, 25%, 50%, 75%, 100%로 5개의 군으로 나누어 스펙트럼 라이브러리를 구축하였다. 스펙트럼의 양상을 토대로 연구지역에서 획득한 초분광 영상에 PLSR (Partial least squares regression) 방법을 적용하였다. 연구결과:구축한 액비의 스펙트럼을 1차, 2차 미분하여 질산성질소의 거동을 확인하였다. 현장실험의 영상을 이용하여 PLSR 농도 추정 모델링을 실시하여 실제 질산성질소의 농도와 비교하였다. 결론: PLSR 농도 추정 모델과 실제 질산성질소의 농도를 비교하였을 때 질산성질소의 농도가 70 mg/kg 이상인 고농도 지역에서 탐지가 가능하다고 판단되었다.

• 한국환경복원기술학회지
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• 제14권6호
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• pp.17-27
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• 2011

Prunus serrulata var. serrulata f. spontanea (E. H. Wilson) C. S. Chang was treated with dried swine excrement at various concentration levels, and their growth reactions and the contents of total kjeldahl nitrogen and total phosphoric acid were analyzed. The result is as follows; 1. When the plants were treated with 0.25% of dried swine excrement, the seed germination rate of Prunus serrulata var. serrulata f. spontanea was higher than that of the control. However, it showed a tendency to decrease when the treatment concentration got higher than 0.25%. 2. The growth rate of species was highest when they were treated with 0.25% of dried swine excrement. It tended to decrease with higher treatment concentration than 0.25%. Significant difference was clear between the control and the experimental plants of Prunus serrulata var. serrulata f. spontanea. 3. The contents of nitrogen and phosphoric acid in Prunus serrulata var. serrulata f. spontanea also got higher as the concentration of dried swine excrement increased. However, the content of total kjeldahl nitrogen was highest in the leaves, and followed by the roots and stems. In contrast, the content of total phosphoric acid were highest in the roots, and followed by the leaves and stems. Therefore, stems had the lowest contents of both nitrogen and phosphoric acid. 4. The contents of total kjeldahl nitrogen and total phosphoric acid in the soil were measured before and after the growth experiment of Prunus serrulata var. serrulata f. spontanea treated with dried swine excrement. The contents of nitrogen and phosphoric acid significantly decreased after the experiment. In conclusion, the contents of total kjeldahl nitrogen and total phosphoric acid accumulated in the plants increased as the concentration level of dried swine excrement got higher. The seed germination and plant growth rates were best at 0.25% treatment of dried swine excrement. The treatment of dried swine excrement may bring high effects on increasing the plant growth rate but could damage the plants with higher concentration than they need. Different optimal concentration levels of dried swine excrement for different plants should be found before it is used as fertilizer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.861-863
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• 1998

As-casted high nitrogen alloys (Fe-25%Mn-12%Cr-1%Ni) have been investigated to study core material. Nitrogen concentration in molten alloys was increased with increasing the square root of nitrogen gas pressure in melting chamber. This result can be explained by Sievert's law. Nitrogen that dissolved as a interstital solid solution element in austenite stainless steel increased lattice parameter and hardness. Electric resistivity($\rho$) was increased with increasing nitrogen concentration and was about $80{\mu}{\Omega}cm$ at room temperature. Coefficient of linear thermal expansion of the nitrogen steel was about $22{\times}10^{-6}/^{\circ}C$.

• 식물조직배양학회지
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• 제28권6호
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• pp.341-346
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• 2001

본 실험에서 Lilium oriental hybrid 'Casa Blanca'. asiatic hybrid 'Mona'와 longiflorum hybrid 'Hinomoto'의 기내 인편으로부터의 자구 형성 및 비대를 위해 MS 배지 내 무기물 농도를 0.5∼2배로, 배지 내 총 질소 농도를 30∼120 mM로 달리하여 자구 형성과 생장을 조사한 결과 인편으로부터의 자구 형성수는 0.5와 1배의 MS 배지 무기물 농도 또는 30 mM의 총 질소 농도에서 'Mona' 품종이 다른 품종에 비해 가장 많았다. 'Casa Blanca'와 'Hinomoto'에서는 0.5배 MS 무기물 농도 또는 30 mM의 질소 농도가 자구 형성에 가장 효과적이었다. 자구 비대는 2배 MS 무기물 농도 또는 120 mM 총질소 농도에서 3품종 모두 양호하였다.

• 한국작물학회지
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• 제44권1호
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• pp.4-10
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• 1999

This study was conducted to determine the effects of NaCl stress on nitrogen, ${NH_4}^+$, and ${NO_3}^-$ content of 4 barley cultivar seedlings that were cultured for 10 and 30 days with different NaCl levels (0, 50, 100, and 150 mM) contain-ing 1/4 Hoagland solutions. The sodium ion content in the shoot of barley seedlings sharply increased with an increase of NaCl concentration. After 30 days of NaCl treatment, the sodium content of the shoot at 150 mM NaCl was 27 times higher than in non-saline conditions. The sodium content in the root linearly increased with increasing NaCl concentration. Nitrogen content in the shoot linearly increased with increasing NaCl concentration, but nitrogen content in the root declined above the point where the $Na^+$ content was 3.0 mM/g $Na^+$ in the barley seedling. ${NO_3}^-$ content also decreased with increasing NaCl concentration. ${NH_4}^+$ content in the shoot decreased with NaCl condition, but its content in the root increased with NaCl condition. A positive correlation between ${NO_3}^-$ and ${NH_4}^+$ content was found in the shoot, but their relationship was negative in the root.

• 한국수산과학회지
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• 제15권1호
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• pp.52-58
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• 1982

염기성 아미노산 (lysine, histidine, arginine)의 과잉투여가 흰쥐의 체중 및 혈액중의 urea nitrogen 농도에 미치는 영향을 조사하였다. $10\%$ casein 먹이와 염기성 아미노산이 각각 $5\%$씩 첨가된 먹이로 28일간 사육한 결과는 아래와 같다. 1. 염기성 아미노산이 과잉 투여된 군은 대조군($10\%$ casein diet)에 비하여 성장율과 사료 섭취율이 감소되었으며 L-histidine HCl 첨가군의 성장이 가장 저조했다. 2. 혈액중의 urea nitrogen 의 농도는 염기성 아미노산이 과잉 투여된 군이 대조군에 비하여 모두 높았으며 L-arginine 첨가군이 가장 높았다. 3. 혈액중의 urea nitron 농도는 사료에 포함된 질소의 양과 관계가 있으며 성장량과는 무관한 것으로 나타났다.

• 청정기술
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• 제17권4호
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• pp.363-369
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• 2011

고농도의 암모니아성질소를 함유하는 폐수의 처리에 전기투석공정의 적용성이 실험적으로 평가되었다. 처리 성능은 전기투석공정의 운전인자 중 유입농도, 운전전압, 그리고 유속이 암모니아성질소의 제거효율에 미치는 영향으로 측정되었다. 한계전류밀도는 유입농도와 유입유속이 증가함에 따라 선형적으로 증가하였고, 유입농도에 따라 목표농도에 도달하는 시간은 직선적인 비례관계를 보였다. 상대적으로 큰 암모니아성질소의 이온당량전도도와 이온이동도로 인하여 유입유속의 증가는 제거속도를 지속적으로 증가시켰다. 또한 운전전압의 증가에 따라 제거속도는 증가하였다. 본 연구에 사용된 전기투석모듈에서 고농도의 암모니아성질소를 제거하는 운전조건으로 유입유속은 3.2 L/min, 운전전압은 한계전류밀도에 해당하는 전압의 80~90%가 추천된다.

• 환경위생공학
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• 제10권1호
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.