• 한국응용곤충학회지
• /
• 제16권3호
• /
• pp.149-154
• /
• 1977

밭 토양에서 Simazine, Nitrofen, Propanil 및 Butachlor 등의 제초제가 시비한 질소의 변화과정에 미치는 영향을 조사하기 위하여 요소와 약제를 처리한 후 $20\pm1^{\circ}C$에서 배양하면서 암모니아태, 아질산태 및 질산태 질소와 pH의 변화를 검토하였던 바 다음과 같은 결과를 얻었다. 1. 요소분해에 의한 암모니아태 질소의 생성에 있어서 모든 약제가 실용농도 수준에서는 아무런 영향이 없었다. Butachlor는 실용농도의 10배와 50배 수준에서, Nirtofen은 50배 수준에서 일시적인 억제효과가 인정되었으나 시일이 경과하면서 정상으로 회복되었다. Simazine과 Propanil은 전 처리수준에서 영향이 없었다. 2. 질화작용에 있어서도 모든 약제가 실용농도수준에서는 영향이 없었다. 실용농도의 10배와 50배 수준에서 Butachlor와 Nitrofen은 아질산의 산화를 억제하였으며 Propanil은 암모니아의 산화를 크게 억제하였으나 아질산의 산화억제 효과는 없었다. 그러나 이 산화억제 효과는 시일이 경과하면서 정상으로 회복되었다. Simazine은 전 처리수준에서, 질화작용에 대해 영향을 인정할 수 없었다. 3. 약제처리구와 무처리구에서의 pH 변화경향은 양 중 질소의 형태변화를 잘 반영하여 주었으며 약에 의한 직접적인 영향은 찾을 수 없었다.

• 한국응용과학기술학회지
• /
• 제27권1호
• /
• pp.29-36
• /
• 2010

The effects of La addition to Ni/$CeO_2$ methane partial oxidation catalysts were investigated. Catalysts were prepared by the impregnation and urea methods. In the preparation of catalysts, La content was changed from 1 wt% to 3wt%. Catalysts that contain 2wt% La showed the highest methane conversion of about 80% and CO selectivity of 84% and $H_2$ selectivity of 70%. This result may be stemmed from that, when La content is 2wt%, a fluorite oxide-type structure is well formed and carbon deposition is also decreased. Among the catalysts, 2.5wt% Ni/Ce(La)Ox showed the highest catalytic activity. From the experiment of changing reaction temperature with 2.5wt% Ni/Ce(La)Ox catalyst, it was found that the optimum reaction temperature is $750^{\circ}C$ and at this temperature methane conversion was about 90%, CO and $H_2$ selectivities were 94 and 80%, respectively.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
• /
• pp.339-342
• /
• 2003

The corrosion characteristics of Copper by oxidizers in Cu CMP slurry has been investigated. Key experimental variables that has been investigate are the corrosion rate by different oxidizers containing slurry of Cu CMP. Oxidizers in Cu CMP slurry reacts with Cu surfaces to raise the oxidation state of the metal via a reduction-oxidation reaction, resulting in either dissolution of the Cu or the formation of Ta surface film on the metal.[1] When Cu films were corroded adding each oxidizer, corrosion rate increased as much as higher Icorrosion. The corrosion rate of Cu was the largest as added $(NH_4)_2S_2O_8$. The higher content of Urea Hydrogen peroxide was, the higher corrosion rate was measured. Putting in tartaric acid as complexing agent, the corrosion rates of the compounds(Urea hydrogen peroxide+$H_2O_2$) are uniformly. As a result of Cu corrosion by $Cu(NO_3)_2$, the high corrosion rate was determined by even small amounts of $Cu(NO_3)_2$. Consequently, this can be explained by assuming that corrosion by oxidizers has primary effects on the removal rate of Cu and the proper oxidizer needs to be chosen in accordance with relationship of each slurry agent.

• 대한기계학회논문집B
• /
• 제41권6호
• /
• pp.397-407
• /
• 2017

본 논문에서는 연비손실 없이 높은 $NO_X$ 저감성능을 보이는 승용 디젤 엔진의 SCR 시스템을 위한 요소수의 분사전략을 제시하였다. 배출되는 $NO_X$량 대비 요소수가 화학량론적 1:1인 피드포워드 분사 전략과 함께 모델기반의 촉매 내 $NH_3$ 흡장률 추정 기법을 통하여 피드백 분사 제어전략을 함께 사용함으로써 과도상태에서 $NO_X$ 저감성능과 $NH_3$ 슬립 성능을 모두 만족시키고자 하였다. 제안된 분사전략을 적용하여 디젤산화촉매기와, 미립자필터가 장착된 2.2L 디젤 엔진을 갖춘 실제 차량에서의 실험을 통하여 제어기의 높은 $NO_X$ 저감률과 낮은 $NH_3$ 슬립 성능을 검증하였다.

• Bulletin of the Korean Chemical Society
• /
• 제26권12호
• /
• pp.2021-2026
• /
• 2005

The oxidation of cytidine 1 and inosine 5 by sodium metaperiodate followed by the reaction of the product with $CH_3I$ in NaOH afforded 2',4'-dihydroxyhexopyranosyl derivatives 2 and 14 respectively. The reaction of thiophene-2-carboxylic acid or furfural with cytidine were taken place via cycloaddition afforded adducts 3 and 4 respectivily. The bromination of inosine 5 or its 2',3'-O-isopropylidine inosine 6 led to the formation of 8-bromoanalogue 7 and 8, respectively. The reaction of 8-bromo-2',3'-O-isopropylidine inosine (8) with ethylglycinate hydrochloride afforded 8-ethoxycarbonylmethylaminoinosine 9. The alkylation of the compound 6 with urea led to the formation of 3-carbonylaminoinosine 10. The oxidation of 6 with DCC afforded 4'-formyl derivative 11, which on reaction with ethyl glycinate hydrochloride followed by reaction with sodium cyanoborohydride afforded 12, while the treatment of dialdehyde inosine 13 with ethyl cyanoacetate in the presence of 0.5 N NaOH afforded compound 15.

• 대한한의학방제학회지
• /
• 제9권1호
• /
• pp.375-385
• /
• 2001

Objectives : This study was carried out to research the protective effects of Sagunja-Tang(SA) through in vivo experiments, and tried to investigate the relation between oxidation of liver tissues and deficiency of Qi. Methods : Acute liver injury which initiated from free radical induced by $CCl_4$, were applied to mice and metabolic data were obtained. In order to measure the degree of liver injury, serum level of alanine aminotransferase(AST), aspartate aminotransferase(ALT), creatinine, blood urea nitrogen(BUN), total protein(TP) and glucose were measured. Lipid peroxidation of liver slice was examined by measuring malondialdehyde(MDA), a product of lipid peroxidation. Results : SA had protective effects on $CCl_4$ induced acute liver injury by decreasing serum level of ALT. Kidney injury was induced by injection of $CCl_4$ too, and SA protected kidney injury by decreasing serum level of creatinine and BUN. Conclusions : Through this study, we found that SA have healing effects on liver and kidney injury of $CCl_4$ induced oxidative stress that is similar to deficiency of Qi. And further studies have to be followed to certify the mechanisms.

• 한국한의학연구원논문집
• /
• 제7권1호
• /
• pp.135-144
• /
• 2001

Objectives : This study was carried out to research the protective effects of Sagunja-Tang(SA) through in vivo experiments, and tried to investigate the relation between oxidation of renal tissues and deficiency of Qi. Methods : Acute renal injury which initiated from free radical induced by $HgCl_2$, were applied to mice and metabolic data were obtained. In order to measure the degree of renal injury, serum level of creatinine, blood urea nitrogen(BUN), total protein(TP) and glucose were measured. Besides, serum level of alanine aminotransferase(AST), aspartate aminotransferase(ALT) were measure too. Lipid peroxidation of renal cortex was examined by measuring malondialdehyde(MDA), a product of lipid peroxidation. Results : SA had protective effects on acute renal injury caused by decrease of glomerular filtration which was initiated by subcutaneous injection of $HgCl_2$. SA protected acute liver injury too. Conclusions : Through this study, we found that SA have healing effects on renal injury of $HgCl_2$ induced oxidative stress that is similar to deficiency of Qi. And further studies have to be followed to certify the mechanisms.

• Clinical and Experimental Pediatrics
• /
• 제62권2호
• /
• pp.43-47
• /
• 2019

Hyperammonemia can be caused by several genetic inborn errors of metabolism including urea cycle defects, organic acidemias, fatty acid oxidation defects, and certain disorders of amino acid metabolism. High levels of ammonia are extremely neurotoxic, leading to astrocyte swelling, brain edema, coma, severe disability, and even death. Thus, emergency treatment for hyperammonemia must be initiated before a precise diagnosis is established. In neonates with hyperammonemia caused by an inborn error of metabolism, a few studies have suggested that peritoneal dialysis, intermittent hemodialysis, and continuous renal replacement therapy (RRT) are effective modalities for decreasing the plasma level of ammonia. In this review, we discuss the current literature related to the use of RRT for treating neonates with hyperammonemia caused by an inborn error of metabolism, including optimal prescriptions, prognosis, and outcomes. We also review the literature on new technologies and instrumentation for RRT in neonates.

• 한국자동차공학회논문집
• /
• 제18권2호
• /
• pp.24-30
• /
• 2010

In this study, numerical experiments were carried out to estimate the SCR De-NOx performance in DOC plus SCR systems. The SCR De-NOx phenomena are described by Langmuir-Hinshelwood reaction scheme. After validating the present approach by comparing the present results with the experimental results, such various parameters as space velocity, $H_2O$ concentration, $NO_2$/NOx ratio and relative volume of DOC are explored to increase the SCR De-NOx performance. The results indicate that SCR De-NOx performance largely depends on space velocity and $NO_2$/NOx ratio, especially below $200^{\circ}C$. SCR De-NOx performance is seriously affected by relative volume of DOC with SCR due to increasing in $NO_2$/NOx ratio at below $250^{\circ}C$.

• 한국수소및신에너지학회논문집
• /
• 제28권1호
• /
• pp.1-8
• /
• 2017

Cu/Mn/Ce catalysts for water gas shift (WGS) reaction were synthesized by urea-nitrate combustion method with the fixed molar ratio of Cu/Mn as 1:4 and 1:1 with the doping concentration of Ce from 0.3 to 0.8 mol%. The prepared catalysts were characterized with SEM, BET, XRD, XPS, $H_2$-TPR, $CO_2$ TPD, $N_2O$ chemisorption analysis. The catalytic activity tests were carried out at a GHSV of $28,000h^{-1}$ and a temperature range of 200 to $400^{\circ}C$. The Cu/Mn(CM) catalysts formed Cu-Mn mixed oxide of spinel structure ($Cu_{1.5}Mn_{1.5}O_4$) and manganese oxides ($MnO_x$). However, when a small amount of Ce was doped, the growth of $Cu_{1.5}Mn_{1.5}O_4$ was inhibited and the degree of Cu dispersion were increased. Also, the doping of Ce on the CM catalyst reduced the reduction temperature and the base site to induce the active site of the catalyst to be exposed on the catalyst surface. From the XPS analysis, it was confirmed that maintaining the oxidation state of Cu appropriately was a main factor in the WGS reaction. Consequently, Ce as support and dopant in the water gas shift reaction catalysts exhibited the enhanced catalytic activities on CM catalysts. We found that proper amount of Ce by preparing catalysts with different Cu/Mn ratios.