• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.229-230
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• 2001

최근, 물이 인류의 생존을 위협하는 문제로 인식되며 중요시되고 있으며, 이는 식수에 대한 국민의 생존권 및 건강권 뿐 아니라 청정하지 못한 수질에서 어획 또는 양식되는 수산자원의 안전성과도 결부되어 중요하게 인식되고 있다. 이는 중금속 뿐 아니라 세균이나 바이러스 등이 먹이연쇄를 통하여 건강을 위협할 수 있기 때문이다. 이로부터 다양한 수처리 기법이 개발되고 있으며, 그 중 하나인 화학적 산화법은 수중 오염물을 화학적으로 산화시켜 생분해성이 좋아지게 하거나 흡착법으로 쉽게 제거될 수 있는 최종 또는 중간 생성물로 변화시키는 방법으로서 염소, 오존, 과산화수소, 과망간칼륨 등이 통용되고 있다. (중략)

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.73-81
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• 1996

The self-diffusion coefficients of chloride and tritiated water ranged from 4.8 $\times$ 10-7 to 7.2 $\times$ 10-7 cm2/sec and 5.5 $\times$ 10-5 to 1.6 $\times$ 10-4 cm2/sec for three different depths of soil constituents at about 50% water content by volume, respectively Mobility of solute and water was conducted under steady-state flow conditions in a field soil consisting of 70 cm of clay to silty clay over a medium sand. A steady-state water flow conditions was maintained by applying irrigation water at a constant flux of 2cm per day. The water labeled with chloride and tritium was leached into the plot during the steady-state condition for 87 days. The positions of tritium and chloride as a function of soil depth and the time was measured by extracting samples of the soil solution with suction probes. Extremes in solute displacement occurred at equal and different depths within the plot. An analysis of these measurements indicated the observations of the pore-water velocity and the apparent diffusion coefficient were log normally disturbed. Twenty-four soil suction probes, used to identify the rate at which a solute was displaced in the soil, will yield an estimate of the mean pore-water velocity of this soils within a range of approximately 5% of its true value providing the effects of potential solute-soil interaction are taken into account.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.407-417
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• 2024

The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.226-226
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• 2021

Tetractycline은 sulfonamides, penicilines 등과 함께 축산계에서 널리 사용되는 대표적인 항생물질의 한 종류이다. 2011년 사료 내 항생제 투여를 금지한 이후 자가치료 및 예방용으로 사용되고 있으며, 가축의 체내로 투여되는 tetracycline는 주로 분뇨에 포함되어 배출되는데, 강우 등 물 순환에 따라 지표수 및 지하수로 이동하여 미생물에 독성을 일으키거나 내성균이 발생하기도 한다. Tetracycline 등의 항생물질 처리 방식으로 흡착 등 다양한 공정이 제시되고 있다. 본 연구에서는 산화제 중 하나인 ferrate(VI)를 이용하여 tetracycline 분해실험을 수행하였다. ferrate(VI)는 염소산화물 및 H₂O₂에 비해 비교적 강한 산화력을 가지며, 처리 후 발생되는 철염(Fe³⁺)은 독성이 없다는 장점이 있다. Ferrate(VI)는 병원균 제거 등에 효과적인 것으로 알려져 있으며, 다양한 난분해성 물질과 항생물질을 성공적으로 분해하여 그 효과를 입증한 바 있다. 본 연구에서는 자체적으로 제조한 potassium ferrate(VI)를 이용하여 다양한 수중 환경에서 tetracycline를 분해하고, 분해특성 및 중간생성물 연구를 수행하였다. Ferrate(VI)는 염기성 환경에서 tetracycline 분해효율이 가장 높은 것으로 나타났으며, 이는 pH에 따른 tetracycline과 ferrate(VI)의 이온화가 가장 큰 원인인 것으로 판단된다. 특히 ferrate(VI)는 pH가 낮을수록 쉽게 환원되는 특징이 있으며, 염기성으로 갈수록 안정화하여 오래 잔류하므로 이러한 결과가 나타난 것으로 판단된다. 중간생성물 조사 결과, ferrate(VI)와 tetracycline 사이의 분해 메커니즘은 주로 OH 라디칼로 인한 것이 대부분이며, hydroxylation과 amino group에서의 demethylation의 형태로 발생하였다. 이후 추가적인 반응으로 benzene ring이 깨지면서 결과적으로 CO₂ 및 H₂O 등으로 무기물화 되는 것으로 판단된다.

• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.180-192
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• 2007

Background: As determined from the recent investigations of discordant cardiac xenotransplantation, hyperacute rejection occurs mainly at the endothelial cells in donor microvascular systems, but this does not occur at cardiac valve leaflets or at medium-to-large caliber vessels. On the basis of this background, this study was performed to look into the biocompatibility for transplantation of a middle or large diameter xenogenic blood vessel by conducting xenogenic arterial transplantation with the carotid artery in a pig-to-goat model. Material and Method: The experimental group was composed of 10 pairs of pig-to-goat combinations. They were divided into each period of 1 week, and 1, 3, 6 and 12 months. Four carotid artery grafts obtained through collection of the bilateral carotid arteries from two pigs were preserved at $-70^{\circ}C$ without other treatment, and then they were transplanted into the bilateral carotid arteries of two goats. Doppler ultrasonography was done on a periodic basis after transplantation to evaluate the patency of the grafted blood vessel. At the ends of a predetermined period, the grafts were explanted from the goats and they underwent gross examination. Hematoxylin-eosin and Masson's trichrome staining were conducted. In addition, in order to examine the immunological rejection of the grafted xenogenic blood vessel, immunohistochemical staining was conducted with T-lymphocyte indicator and von Willebrand factor. Result: Two goats at the each one-week period and the one-year period died during the experimental period because of a reason unrelated to the experimental procedure, and the remaining 8 goats survived until the end of each experiment period. On Doppler ultrasonography, unilateral carotid artery occlusion was found in a goat, whose period was specified as 3 months, among the 8 survived goats. However, the vascular patency was maintained well and there was no graft that formed aneurysms in the other goats. On gross examination, the region of vascular anastomosis was preserved well, and calcification of the grafted blood vessel was not shown. Histologically, the endothelial cells of the graft disappeared one week after transplantation, and then there was progressive spread of the recipients' endothelial cells from the anastomotic site. The reendothelialization occurred over the whole graft at one month after transplantation. The neointimal thickening and adventitial inflammation became severe by 3 months after transplantation, but this lessened at 6 months and 12 months, respectively. The rate of CD3 positive cells was very low among the infiltrated inflammatory cells. Conclusion: The fresh-frozen xenogenic artery kept its patency without being greatly influenced by xenogenic immune reaction.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.191-196
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• 2001

${\alpha},{\beta}$-Unsaturated carboxanilides 5 with trifluromethylated dihydro-1,4-oxathiins were synthesized for the development of new agrochemical fungicide. Chlorination of trifluoromethylated ${\beta}-keto$ ester 6 followed by the reaction with 1,2-mercaptoethanol gave intermediate 1,4-oxathiane 11. Without purification of 11, substitution of hydroxy group by chlorine, followed by dehydrochlorination of 10 in the presence of triethylamine afforded trifluoromethylated dihydro-1,4-oxathiin ethyl ester 9. Acylation of the hydroxy group of the carboxylic acid 12 followed by treatment of various amines gave the corresponding trifluoromethylated dihydro-1,4-oxathiin carboxamides 5. Antifungal screening (in vivo) of the synthesized compounds against typical plant diseases, which include rice blast, rice sheath blight, cucumber gray mold, tomato late blight, wheat leaf rust, and barley powdery mildew, was carried out. Where meta position of the phenyl group was substituted with isopropoxy or isopropyl group, excellent antifungal activities against rice sheath blight and wheat leaf rust were detected.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.26-32
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• 2001

[ ${\alpha},{\beta}$ ]-Unsaturated carboxamides 12 with trifluromethylated dihydro-1,4-dithiins were synthesized for the purpose of development of new agrochemical fungicide. Chlorination of trifluoromethylated ${\beta}$-ketoester 4 followed by tile reaction with 1,2-ethanedithiol gave intermediate 1,4-dithiane 9. Without purification of 9 substitution of hydroxy by chlorine followed by dehydrochlorination in the presence of triethylamine afforded trifluoromethylated dihydro-1,4-dithiin ethyl ester 7. Activation of the hydroxy of the carboxylic acid 10 obtained from the hydrolysis of 7 and then reacted with various amines gave the corresponding trifluoromethylated dihydro-1,4-dithiin carboxamides. Antifungal screening (in vivo) against typical plant diseases, Rice Blast, Rice Sheath Blight, Cucumber Gray Mold, Tomato Late Blight, Wheat Leaf Rust, and Barley Powdery Mildew of the synthesized compounds was carried out. As a result, most of the compounds shlowed weak antifungal activities and some compounds in which isopropyl group was substituted in meta of the phenyl showed antifungal activity (99%) at 250 ppm against the disease Wheat Leaf Rust.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.13-17
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• 2001

A synthesis of new 2-phenylimino-1,3-thiazolines 2 for the purpose of development of new agrochemical fuugicide was described. Reaction of chlorine with diketene followed by treatment of benzylamine without isolation of intermediate 8a gave ${\gamma}-chloro-{\beta}-keto$ benzylamide 10a. Thioureas 4 obtained from the reaction of methyl isothiocyanate with aniline derivatives were subjected to 10a in acetone solution to afford the corresponding 2-phenylimino-1,3-thiazoline hydrochloric acid salts 2 through unisolable inltermediates 11 and 12. The plausible reaction mechanism including nucleophilic attack of sulfur assisted neighboring nitrogen lone pair electron on phenyl of thiourea 4 was discussed.

• Journal of Life Science
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• v.20 no.12
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• pp.1906-1909
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• 2010

Acid and halide ion catalyses for the hydrolysis of benzenesulfinamides were kinetically investigated. The rates of hydrolysis increased with increasing concentration of both acid and halide ions and also showed to speed up as the electron donating ability of the benzenesulfinyl moiety and the electron withdrawing ability in the leaving group increased. The reactivity of halide ions was in the order of $Br^-$ > $Cl^-$. The reaction mechanism may be accommodated by including a hypervalent intermediate and sulfonium cation.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.426-436
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• 1985

Preparative and kinetic photochemical reactions of several benzanilides were studied. Several substituted benzanilides were synthesized by acylation of substituted anilines with substituted benzoyl chlorides. While benzanilide gave a photo-Fries type reaction product, 2-chlorobenzaniline, 2-bromobenzanilide, and 2-methoxybenzanilide gave a photocyclization reaction product, phenanthridone. Since 8-chlorophenanthridone was obtained from 2,2'-dichlorobenzanilide, the carbonyl phenyl is the excited site. Quantum yield of photocyclization of 2-chlorobenzanilide, 2'-chlorobenzanilide, and 2-methoxybenzanilide were obtained. 2-Chlorobenzanilide was photocyclized effectively and 2'-chlorobenzanilide ineffectively. Since the oxygen present in the reaction medium retarded the photocyclization reaction of 2-chlorobenzanilide, the triplet state of 2-chlorobenzanilide is involved. The mechanism of the photocyclization of 2-chlorobenzanilide is suggested: $\pi-complex$ between carbonyl phenyl and N-phenyl was formed from the triplet state of 2-chlorobenzanilide; neighbour phenyl (N-phenyl) assists for leaving of chlorine from carbonyl phenyl to make an intermediate, cyclized conjugated radical, because electron donating group on the N-phenyl ring accelerated the reaction; hydrogen detachment from the intermediate is obviously not a rate determined step because there was no isotope effect on the rate of photocyclization. The photocyclization reaction rate of 2-methoxybenzanilide was faster in the presence of oxygen than in the absence of oxygen. Thus, the singlet excited state of 2-methoxybenzanilide is involved in the reaction. Probably, the intermediate, methoxyhydro-phenanthridone is oxidized by oxygen in the medium to give phenanthridone.