• Archives of Pharmacal Research
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• 제13권4호
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• pp.351-354
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• 1990

2, 3-diphenyl-4-cyano-pyrrole-5-thione (4) was either by the reaction of benzoin (1) and cyanothioacetamide (3) followed by cyclization using AcOH/sodium acetate or by refluxing a mixture of benzoin (1) and cyanothioacethamide in pyridine to afford directly 4. Several new pyrrole and pyrazole derivatives were synthesised using 4 as synthon. The structure of the newly synthesised derivatives were based on celemental and spectral data studies. Methylation of the SH group in 4 afforded 5. Reaction of 4 with ethyl bromo acetate afforded (6). Treatment of (5) and (6) with hydrazine hydrate afforded the same pyrazole derivative (10) through the intermediate (9). Treatment of 6 with aniline and phenylhydrazine afforded the pyrrole derivatives 8a, b respectively. Treatment of 6 while dill HCI gave 2, 3-diphenyl-4-cyano-pyrrole-5-one (7). Treatment of 6 with $NH_3$/EtOH afforded the amidic derivatives (11) with treatment of 6 $NH_3$/ heat then acidification it gave the carboxylic derivatives (12).

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1892-1900
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• 2023

A protective oxide layer forms on the material surfaces of a Nuclear Power Plant during operation due to high temperature. These oxides can host radionuclides, the activated corrosion products of fission products, resulting in decommissioning workers' exposure. These deposited oxides are iron oxides such as Fe₃O₄, Fe₂O₃ and mixed ferrites such as nickel ferrites, chromium ferrites, and cobalt ferrites. Developing a new chemical decontamination technology for domestic CANDU-type reactors is challenging due to variations in oxide compositions from different structural materials in a Pressurized Water Reactor (PWR) system. The Korea Atomic Energy Research Institute (KAERI) has already developed a chemical decontamination process for PWRs called 'HyBRID' (Hydrazine-Based Reductive metal Ion Decontamination) that does not use organic acids or organic chelating agents at all. As the first step to developing a new chemical decontamination technology for the Pressurized Heavy Water Reactor (PHWR) system, we investigated magnetite dissolution behaviors in various HyBRID inorganic acidic solutions to assess their applicability to the PHWR reactor system, which forms a thicker oxide film.

• 동아시아식생활학회지
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• 제16권6호
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• pp.740-746
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• 2006

The proximates, vitamin C, minerals, and fatty acids of five potato cultivars were evaluated by AOAC methods, the hydrazine method, ICP-AES, and gas chromatography, respectively. The proximate analyses; vitamin C, reducing sugar, and soluble solid contents; and mineral and fatty acid compositions were significantly different among the five cultivars. The Superior cultivar contained a higher carbohydrate content and higher Ca/P ratio and lower levels of crude protein and Na. The Atlantic cultivar contained significantly higher amount of energy, carbohydrate, reducing sugar, vitamin C, SEA, and MUFA, and significantly lower amount of minerals and PUFA. The Shepody cultivar contained significantly higher amount of carbohydrate and MUFA, and significantly lower amount of soluble solid, vitamin C, and SFA. In addition, the P, Fe, Mg, Cu, and Al levels were significantly higher in Shepody, and Zn content was significantly lower. The Jopung cultivar contained significantly higher levels of moisture and Na, and significantly lower levels of soluble content, reducing sugar, carbohydrate, crude protein, and fat. Finally, the Namsuh cultivar contained significantly higher amount of soluble solid, crude protein, K, Mg, and Al, and significantly lower amount of reducing sugar.

• 전기전자학회논문지
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• 제13권4호
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• pp.37-42
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• 2009

본 연구에서는 졸겔법으로 ZnO, 수열합성법으로 $SnO_2$ 나노분말을 제조하고 이들 나노분말에 Pd, Ru 등의 촉매를 첨가하였다. MEMS 기술로 제작된 히터 및 전극 구조 위에 나노 감지 분말을 도포하여 CO and $NO_2$ 가스 센서를 제작하였다. 0.1 wt% Pd 도핑된 $SnO_2$ 가스센서와 Ru 도핑된 ZnO 가스 센서는 각각 CO 30 ppm, $NO_2$ 1 ppm의 낮은 농도에서도 높은 감지 특성을 보였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.487-492
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• 2012

Trace element zinc deficiency or excess is implicated in the development or progression of some cancers. The exact role of zinc in the etiology of colon cancer is unclear. To cast light on this question, an experimental model of colon carcinogenesis was applied here. Six week old rats were given sub cutaneous injections of DMH (30 mg/kg body weight) twice a week for three months and sacrificed after 4 months (precancer model) and 6 months (cancer model). Plasma zinc levels showed a significant decrease (p<0.05) at 4 months and a greater significant decrease at 6 months (p<0.01) as compared with controls. In the large intestine there was a significant decrease in tissue zinc levels (p<0.005) and in CuZnSOD, and alkaline phosphatase activity (p<0.05) in the pre-cancerous model and a greater significant decrease in tissue zinc (p<0.0001), and in CuZnSOD and alkaline phosphatase activity (p<0.001), in the carcinoma model. The tissue zinc levels showed a significant decrease in the small intestine and stomach (p<0.005) and in liver (p<0.05) in the cancer model. 87% of the rats in the precancer group and 92% rats in the cancer group showed histological evidence of precancerous lesions and carcinomas respectively in the colon mucosa. This study suggests that the decrease in plasma zinc, tissue zinc and activity of zinc related enzymes are associated with the development of preneoplastic lesions and these biochemical parameters further decrease with progression to carcinoma in the colon.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.288-293
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• 2001

This paper presents the water-hammer effect due to the rapid opening and closing of isolation valve and thruster valve in the spacecraft propulsion system. The single propellant feed system was modeled to investigate the maximum peak pressure due to the water-hammer effect. The test parameters are tank supply pressure, shape and throat length of orifice and line length. Kerosene was used as the inert simulant propellant liquid instead of hydrazine. As downstream line length after isolation valve increased from 1.5 to 2.5m, the maximum line-filling water-hammer peak pressure decreased, but the average time interval between peak pressures increased. The maximum line-filling water-hammer peak pressure with orifice was lower than without orifice, and the maximum line-filling water-hammer peak pressure with orifice at the back of isolation valve was lower than with orifice in front of isolation valve. Without orifice, the maximum water-hammer peak pressure due to the rapid opening and closing of the thruster valve was about 126% of tank supply pressure. With orifice, it decreased. As orifice throat length increased, it decreased. The maximum water-hammer peak pressure due to the rapid closing of the thruster valve with converging-diverging orifice was lower than normal orifice. It was found that the orifice as a means of pressure drop was very effective to reduce the water hammer peak pressure at the thruster valve. The results of this study can be used for the design of spacecraft liquid propulsion feed system.

• 방사성폐기물학회지
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• 제3권1호
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• pp.41-47
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• 2005

Cs$^{+}$ 이온에 대해 선택성을 갖는 ferrocyanide-음이온 교환수지를 제조하여 모의 제 염폐액 내에 존재하는 Cs$^{+}$ 이온에 대한 흡착실험을 수행하였다. 제조된 이온교환 수지가 citric acid를 주제염제로 하는 제염폐액 내에 존재하는 Cs+ 이온에 대한 흡착능력은 상용 양이온교환수지에 비해 4배 이상 효과적인 것으로 나타났다. 모의 제염폐액과 선택성 이온교환수지를 접촉시킨 후 360분이 경과하면 금속이온에 대한 흡착반웅이 평형에 도달하였다. 본 연구범위에서 Co$^{2+}$ 이온농도가 필요이상 증가하게 되면 Cs$^{+}$ 이온의 흡착율은 감소하였다. 과산화수소와 히드라진을 사용한 선택성 폐 이온교환수지의 재생실험 결과 전기중성화조건을 만족시키기 위해 Cs$^{+}$ 이온이 수지로부터 용출됨을 확인하였고 열화없이 재 사용가능성을 확인하였다.

• 한국항공우주학회지
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• 제37권7호
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• pp.717-728
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• 2009

로켓추진기관에 있어 과산화수소는 단일추진제와 이종추진제의 산화제로 사용되어 왔다. 과산화수소는 추력기용으로 사용된 최초의 단일추진제였으나, 후에 보다 비추력이 높고 저장성이 좋은 하이드라진으로 대체되었고, 터보펌프 구동용으로는 여전히 사용되어지고 있다. 이종추진제의 산화제로서는 1970년대까지 사용되었다. 1990년대에 들어서 저비용, 친환경적인 개발이 중요하게 대두되면서 과산화수소는 다시 개발자들의 관심의 대상이 되었다. 과산화수소의 저장성능이 과거에 비해 크게 개선되었으며, 케로신/과산화수소를 추진제 조합으로 사용하는 경우 케로신/액체산소를 사용하는 경우에 비하여 가속성능은 다소 떨어지나, 높은 추진제밀도와 O/F 비로 인하여 유사한 가속성능을 얻을 수 있으며, 연소생성물 역시 더욱 청정하였다.

• 한국어병학회지
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• 제20권3호
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• pp.307-313
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• 2007

In this study, a QCM biosensor was made to detect Edwardsiella tarda (E. tarda) using a specific antibody. A 9 MHz AT-cut piezoelectric wafer layered with two gold electrodes of 5mm diameter had a reproducibility of 0.1 Hz in frequency response and was used as the transducer of the QCM biosensor. Self assembled layer (SAM) was conformed on a quartz crystal by treating with 3-mer-captopropionic acid (MPA) and activated with N-ethyl-N'-(3-dimethyl-aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The resulting NHS group was further converted to hydrazide by the reaction with hydrazine. Aldehyde group was introduced into the carbohydrate moiety of anti-E. tarda antibody by the reaction with periodic acid and was used to immobilise the antibody through the reaction with hydrazide group on the electrode surface. A baseline was established in the presence of phosphate-buffered saline (PBS) and a resonant frequency (F1) was measured. Sample was added to the sensor surface and second resonant frequency (F2) was measured after unbound substances were washed out with PBS several times. Finally, the frequency shift (ΔF) representing the mass change was calculated by subtracting F2 from F1. After adding the oxidized anti-E. tarda antibody to the electrode surface containing hydrazide group, frequency shift of 288.811.4 Hz (mean S.E) was observed, thus proving that considerable amount of antibody was immobilized. In the immunoassay test, the frequency shift of 1877.75 Hz, 580.67 Hz, 221.39 Hz, 7.671.83 Hz (mean S.E) were observed at doses of 1000, 500, 100, 50 g of bacterial cells, respectively. It was also demonstrated that the prepared sensor chip was stable enough to withstand repeated surface regeneration with 0.2 M Tris-glycine and 1 % DMSO, pH 2.3 more than ten times.

• 한국미생물·생명공학회지
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• 제6권4호
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• pp.155-159
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• 1978

분리된 효모에 의한 aromatic ring compound의 전환반응 실험에 앞서 phenol 자화능에 대한 환경 인자의 영향을 조사하기 위하여 phenol을 유일한 탄소원으로 사용하여 분리된 효모균을 30시간, 3$0^{\circ}C$에서 진탕배양하여 균체증식량을 측정하였다. 1) pH3.5~4.5 온도 35$^{\circ}C$에서 가장 자화능이 우수하였으며 phenol의 처음 농도 1000ppm 까지 는 쉽게 이용할 수 있었고 2000ppm에서는 5 일간 배양시켰을 때 비로소 균체증식이 나타났다. 2) pH 5.0, 배양온도 3$0^{\circ}C$에서 본 균의 maximum specific growth rate는 0.27hr-1 이었으며, phenol 을 1000ppm씩 단계적으로 첨가하면서 phenol 소비율에 대한 균체수율 정수 Y값을 구한 결과 Y=3.2였다. 3) Yeast extract를 필수영양원으로 첨가할 때 0.005~0.01% 농도에서 가장 효과적이었으며, 또 산화환원소 효소 조해제인 HgCl$_2$, phenylhydrazine 을 명명 $10^{-5}$M, $10^{-3}$M을 배지내에 첨가하면 분리된 효모균의 증식을 거의 볼 수 없었다. 4) Phenol의 자화에 명종 실소원의 효과를 비교 해 본 결과 urea가 가장 효과적이었고, 이 효모균은 phenol 외에 catechol, resorcinol, benzidine 을 자화할 수 있다