• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.247-252
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• 2009

The egg development and early life history of the Korean endangered fish Koreocobitis naktongensis (Cobitidae) were investigated. Eggs from the females were obtained by injecting 10 IU/g of human chorionic gonadotropin and inseminated with sperm by the dry method in the laboratory. The fertilized eggs were 1.0~1.2 mm in diameter and had no oil globules. The embryo began to hatch about 38 hrs after fertilization under water temperature of $20{\pm}1^{\circ}C$. The newly-hatched larvae were 2.6~2.8 mm in total length, and their mouth and anus were not yet opened. Seven days after hatching, the postlarvae were 4.5~5.2 mm in total length, and their yolk sacs were completely absorbed. They entered the juvenile stage when all fin-rays were formed at 50 days after hatching, and their total lengths were 21~27 mm.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.349-352
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• 2002

The effects of Mn on growth and nutrient status of Pinus densiflora seedlings grown in a nutrient culture solution were investigated. Mn concentrations was added as manganese chloride at 0, 30 and 60ppm to the nutrient culture solution. The 2-year-old seedlings were transplanted into the solution maintained at pH 4.0, and grown for 90 days in a greenhouse. The Mn treatment induced a significant reduction in the dry weight growth of the seedlings. The relative growth rate(RGR) and net assimilation rate(NAR) of the seedlings decreased with increasing Mn concentrations in the nutrient culture solutions. For the nutrient status of the seedlings, Ca and Mg content in trunk and root was least in 60ppm Mn treatment, and Mn content in needle was about 3 times more than in root. Also the net photosynthetic rate of the seedlings was significantly lower both in 30ppm and 60ppm Mn treatment compared to them in 0ppm. This result suggests that the reductions in the RGR and NAR of the seedlings may be resulted from the inhibition of net photosynthesis by the mixed effect of lower nutrient uptake of roots and excess accumulation of Mn in needle.

• Korean Journal of Environmental Agriculture
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• v.30 no.1
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• pp.68-75
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• 2011

BACKGROUND: To assess and prevent the environmental impacts and risks by veterinary pharmaceuticals, Guidance on Estimating Soil Persistence and Degradation Kinetics from Environmental Fate Studies on Veterinary Pharmaceuticals for Environmental Risk Assessment was proposed. METHODS AND RESULTS: Proposed guidance was coined by VICH, EU guideline, OECD guideline and soil dissipation studies for the purpose of international harmonizing. Guidance was also modified from pesticide soil persistence testing guidelines of US, EU, and Korea, with practical approaches adopting in-use test guideline for Korea. CONCLUSION(S): Proposed guidance are consisted of three parts; Laboratory Soil Experiment, Field Soil Dissipation Study, and Estimation of $DT_{50}/DT_{90}$. Proposed guidance is to be available for the requirement for registration of veterinary pharmaceuticals with fit for purpose in Korea.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.250-255
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• 2015

In fully edentulous cases, which are accompanied by severe residual ridge resorption and impairment of supporting tissues of complete dentures, proper diagnosis and systemic treatment planning are required for the improvement in retention, stability, and support of prosthesis. Provisional restoration, while it is unfamiliar in complete denture restoration, can be used as a valuable tool, which makes possible to evaluate the stability of complete dentures and receive feedback from patients in complex clinical situations. In this case, a provisional denture was used to improve stability of impression, polished, and occlusal surfaces of complete denture, and to consider esthetic requirements before final denture construction. The result was clinically satisfactory in terms of functional and esthetical aspects.

• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.146-153
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• 2000

The development of larvae and juvenile of the smoothskin sculpin (Ocynectes modestus) caught at Pusan brook in May and June 1995 was described. Yolk was completely absorbed when the larvae was about 6.28 mm in average standard length (ASL) with 32~33 myomeres. Flexion of the notochord started when the juvenile was about 7.36 mm in ASL and finished about 9.34 mm in ASL, respectively. Aggregate numbers of all fin rays were completed at over 10.08 mm in ASL, when the larvae reached the juvenile stage. One pairs of flaps were observed on the dorsal surface of the head at 10.08 mm in ASL. The juveniles longer then 14.00 mm in ASL has the same pigment pattern as that of adults. A new Korean name "Min-Ga-Si-Ggeog-Jeong-i" is proposed for this species.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.382-388
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• 1992

Mycelial growth inhibition activity of forty-one N-substituted phenyl 5-chloro-1,3-dimethylpyrazole-4-carboxamides against Rhizoctonia solani was analysed quantitatively by multiple regression analysis using physicochemical parameters of substituents as independent variables and $pEC_{50}$ as dependent variable. As a result, a quantitative structure-activity relationship was formulated using eight physicochemical parameters, which explains 83% of variance of the fungicidal activity. The most important parameter for the biological activity was log k', as related to the penetration and transport processes in the biological system. The activity also correlated with other hydrophobic parameters$({\pi}_2,\;{\pi}_3)$, an electronic parameter$({\Sigma}{\sigma})$, and steric parameters$(STERIMOL\;parameters\;L_3,\;L_4)$.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.464-464
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• 2023

최근 이산화탄소(Carbon Dioxode, CO₂) 배출량 증가로 인하여 지구온난화와 같은 기후변화 문제가 심각한 사회 문제로 대두되고 있다. 이에 따라 2015년 12월 12일 프랑스 파리에서 열린 제21차 유엔기후변화협약에서 교토의정서를 대체하는 파리협정(Paris Agreement)을 채택하였으며, 국내에서는 이러한 국제사회의 기후변화 대응에 동참하고 온실가스 감축을 이행하기 위한 2050 탄소중립 정책을 추진하였다. 이산화탄소를 다량으로 발생시키는 철강·산업·건설·에너지 분야 중건설 분야에서 배출되는 이산화탄소는 전체 배출량의 19.9%로 특히 시멘트를 제조하는 과정에서 많은 양의 이산화탄소가 배출되고 있다. 기존의 건설 분야 에서는 이산화탄소를 저감하기 위해 콘크리트 배합 또는 양생과정에서 챔버 내 이산화탄소를 가스 형태로 주입하여 탄산화 반응을 통해 콘크리트 내부에 이산화탄소를 영구히 저장시키고자 하였다. 그러나 이는 챔버 사용, 양생조건 등 적용 조건이 제한적이며, 콘크리트 내 이산화탄소 흡수 효율이 높지 않아 이를 개선할 수 있는 기술이 필요하다. 이를 개선하기 위해 최근에는 콘크리트 배합수 내 이산화탄소를 용해시켜 배합과정에서 콘크리트 내부로 이산화탄소를 강제로 인입시키는 연구들이 진행되고 있다. 그러나 콘크리트 배합수로 사용되고 있는 일반물이나 지하수의 경우 가압을 하여도 약 1,400mg/L의 이산화탄소를 용해시키며, 가압을 통해 용해된 이산화탄소는 쉽게 대기 중으로 방출되는 한계점을 지니고 있어 현장에서 사용하기 어려운 문제가 있다. 이러한 한계점을 극복하기 위해서 본 연구에서는 200nm 이하의 크기를 가지는 나노버블기술을 이용해 압력을 가하지 않은 상태에서 수중에 이산화탄소를 용해시킬 수 있는 시스템을 개발하고자 한다. 나노버블기술을 이용한 수중 이산화탄소용해 시스템을 통해 수중에 이산화탄소를 용해시켜 콘크리트 배합수로 활용하기 위한 기초 연구가 될 것으로 판단된다.

• Korean Journal of Ichthyology
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• v.13 no.3
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• pp.181-189
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• 2001

Spawning behavior of the Takifugu pardarlis (Temminck et Schlegel) was observed on the Jook-do coast in Tongyong from March 1997 to June 1999. The spawning ground was locted in the intertidal zone between Tongyong and Koje-do. Its bottom was mainly gravels and stones, and its depth was 0.5~1.0 m. Spawning season was from the end of the March to the middle of May. During the spawning season, the mature fishes formed school a of 10~30 individuals, then moved to the spawning ground together. When a mature female spawned eggs, the attendant males fertilized them at the same time. The fertilized eggs obtained from the parent fishes caught at the spawning ground were adhesive, opaque and spherical, measuring 1.14~1.24 mm (mean 1.19 mm, n = 50) in diameter with numerous tiny oil globules. Hatching period was about 205 hours after fertilization at water temperature of $18.0{\pm}0.5^{\circ}C$. The newly hatched larvae were 2.92~3.10 mm (mean 3.01 mm, n = 20) in total length (TL), had a large yolk, and 11~13+14~15 = 25~28 myomeres. At 5 days, the larvae had attained 3.79~3.85 mm (mean 3.82 mm, n = 20) in TL and had transformed into the postlarval stage. At 15 days, the postlarvae had attained 7.78~7.90 mm (mean 7.84 mm, n = 20) in TL. At 21 days, had larvae attained 10.15~10.27 mm (mean 10.21 mm, n = 20) in TL and had reached the juvenile stage. All fins were formed with a complete set of fin rays having the following counts: dorsal fin rays 11~12; anal fin rays 9; pectoral fin rays 14~15; caudal fin rays 11~12.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.299-308
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• 2004

In order to elucidate the behavior of bensulfuron-methyl, a sulfonylurea herbicide, in a soil/plant microecosystem, rice plants (Oryza sativa L.) were grown for 12 weeks in the specially made stainless steel pots (17cm I.D. $\times$ 10cm H.) containing two different paddy soils treated with fresh and 13-week-aged residues of [phenyl-$^{14}C$]bensulfuron-methyl, respectively. During the aging period, the mineralization to $^{14}CO_2$ from soil A (OM, 3.59%; CEC, 7.65 $cmol^+\;kg^{-1}$; texture, sandy clay loam) and B (OM, 1.62%; CEC, 4.51 $cmol^+\;kg^{-1}$; texture, sandy loam) amounted to 6.79 and 10.15% of the originally applied $[^{14}C]$bensulfuron-methyl, respectively. The amounts of $^{14}CO_2$ evolved from the soils with fresh residues were higher than those from the soils with aged residues. At harvest after 12-week growing, $^{14}C$-radioactivity absorbed and translocated into rice plants from soils A and B containing fresh residues of bensulfuron-methyl was 1.53 and 4.40%, while 4.04 and 6.37% in the two soils containing aged residues, respectively. Irrespective of aging and soil type, the $^{14}C$-radioactivity remaining in soil ranged from 80.41 to 98.87% of the originally applied $[^{14}C]$bensulfuron-methyl. The solvent extractability of tile soils was $39.25\sim70.39%$, showing the big differences among the treatments. Most of the nonextractable soil-bound residues of $[^{14}C]$bensulfuron-methyl were incorporated into the fulvic acid fraction$(61.32\sim76.45%)$. Comparing the microbial activity of the soils with rice plants grown with that of the soils without them, the former was $1.6\sim3.0$ times higher than the latter. However, it did not correlate with the $^{14}CO_2$ evolution.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.172-182
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• 2006

This study was designed to assess molinate fate in the lysimeter by measuring the total radioactivity in the leachate, evolved $^{14}CO_2$, and $^{14}C$-residues in soil and rice plant. The amounts of applied $^{14}C$ in the leachate from the lysimeter for 20 weeks were 1.05% in 2.31 pore volume (217,465 mL) at the first and 0.34% in the second year, respectively. The amount of $^{14}CO_2$ evolved from the lysimeter accounted for 6.47% and 0.03% of applied $^{14}C$ in the first and second year. The $^{14}C$-activities in the soil layer of the lysimeter were distributed 18.0% (1st) and 13.3%(2nd) in the depth of 0 to 10 cm, 4.3 (1st) and 1.1% (2nd) in the depth of 10 to 20 cm. Most of the applied $^{14}C$ was detected in the top 20 cm soil layer. Total $^{14}C$ in rice plants grown at lysimeter were detected 11.46% of applied $^{14}C$. 11.11% in straw, 0.24% in brown rice grain, 0.08% in chaff and 0.03% in ears were distributed in the first year. Consequently, environmental fate of molinate using lysimeter simulating a paddy rice field were investigated 25.24% in soil, 11.64% in rice plant, 1.05% in leachate, 6.74% in evolved $^{14}CO_2$ and 0.02% in volatilized organic chemicals in the first year.