• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.60-67
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• 2020

In this study, copper (II) oxide powder for electroplating was prepared by recovering CuCl₂ from NaClO₃ type etching wastes via recovered non-sintering two step chemical reaction. In case of alkali copper carbonate [mCuCo₃·nCu(OH)₂], first reaction product, CuCo₃ is produced more than Cu(OH)₂ when the reaction molar ratio of sodium carbonate is low, since m is larger than n. As the reaction molar ratio of sodium carbonate increased, m is larger than n and Cu(OH)₂ was produced more than CuCO₃. In the case of m has same values as n, the optimum reaction mole ratio was 1.44 at the reaction temperature of 80℃ based on the theoretical copper content of 57.5 wt. %. The optimum amount of sodium hydroxide was 120 g at 80℃ for production of copper (II) oxide prepared by using basic copper carbonate product of first reaction. At this time, the yield of copper (II) oxide was 96.6 wt.%. Also, the chloride ion concentration was 9.7 mg/L. The properties of produced copper (II) oxide such as mean particle size, dissolution time for sulfuric acid, and repose angle were 19.5 mm, 64 second, and 34.8°, respectively. As a result of the hole filling test, it was found that the copper oxide (II) prepared with 120 g of sodium hydroxide, the optimum amount of basic hydroxide for copper carbonate, has a hole filling of 11.0 mm, which satisfies the general hole filling management range of 15 mm or less.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.3
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• pp.145-149
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• 2018

The objective of this study was to determine the effect of injection application of pig slurry on ammonia ($NH_3$) and nitrous oxide ($N_2O$) emission from timothy (Phleum pretense L.) sward. The three treatments were applied: 1) only water as a control, 2) pig slurry application by broadcasting, 3) pig slurry application by injection. The pig slurry was applied at a rate of $200kg\;N\;ha^{-1}$. Total $NH_3$ and $N_2O$ emission, expressed as a cumulative amount throughout the measurement time (40 days), was $2.68kg\;NH_3-N\;ha^{-1}$ and $6.58g\;N_2O-N\;ha^{-1}$, respectively, in the control. The injection application of pig slurry decreased total $NH_3$ and $N_2O$ emission by 39.8% and 33.3%, respectively, compared to broadcasting application of pig slurry. The present study clearly showed that injection application exhibited positive roles in reducing N losses through $NH_3$ and $N_2O$ emission.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.106-112
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• 2014

The diesel engine, which has high compression ratio than other heat engines, has been using as the main power source of marine transport. Especially, since marine diesel engines offer better specific fuel consumption (SFC), it is environment-friendly compared to those used in other industries. However, attentio should be focused on emissions such as nitrous oxide ($N_2O$) which is generated from combustion of low-grade fuels. Because $N_2O$ in the atmosphere is very stable, the global warming potential (GWP) of $N_2O$ is 310 times as large as that of $CO_2$, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. It has been hitherto noted on the $N_2O$ exhaust characteristics from stationary power plants and land transportations, but reports on $N_2O$ emission from the marine diesel engine are very limited. In this experimental study, a author investigated $N_2O$ emission characteristics by using changed diesel fuel components of nitrogen and sulfur concentration, assessed on the factors which affect $N_2O$ generation in combustion. The experimental results showed that $N_2O$ emission exhibited increasement with increasing of sulfur concentration in fuel. However, all kinds of nitrogen component additives used in experiment could not change $N_2O$ emission.

• Journal of Korea Water Resources Association
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• v.42 no.8
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• pp.631-641
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• 2009

Transport of nitrous oxide and treated waste water was investigated in an estuary receiving treated waste water. Seasonal change of water quality were also observed to assure origins of $N_2O$ and to estimate the influence of treated waste water on $N_2O$ production in the survey area. Based on nitrous oxide concentration profiles in the survey area, discharged treated waste water were traced, which flowed upstream at the flood tide and downstream at the ebb tide with concentration maxima. It is assumed that nitrous oxide discharged from treated waste water is transported to the survey area with partial and vertical mixture. To determine the production of $N_2O$ in survey area, flux at each sampling sites were calculated and 25% of the produced $N_2O$ was originated from treated waste water in result. The remaining percentage of the production was also assumed to be the discharge from the sediment layers.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.368-373
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• 2014

Ammonia loss from urea significantly hinders efficient use of urea in agriculture. The level of nitrous oxide ($N_2O$) a long-lived greenhouse gas in atmosphere has increased mainly due to anthropogenic source, especially application of nitrogen fertilizers. There are reports in the literature showing that the addition of zeolite to N sources can improve the nitrogen use efficiency. This study was conducted to evaluate nitrous oxide ($N_2O$) and ammonia ($NH_3$) emission by mixed treatment of urea and zeolite in upland crop field. Urea fertilizer and zeolite were applied at different rates to study their effect on $N_2O$ emission during red pepper cultivation in upland soils. The $N_2O$ gas was collected by static closed chamber method and measured by gas chromatography. Ammonia concentration was analyzed by closed-dynamic air flow system method. The total $N_2O$ flux increased in proportion to the level of N application. Emission of $N_2O$ from the field increased from the plots applied with urea-zeolite mixture compared to urea alone. But urea-zeolite mixture treatment reduced about 30% of $NH_3$-N volatilization amounts. These results showed that the application of urea and zeolite mixture had a positive influence on reduction of $NH_3$ volatilization, but led to the increase in $N_2O$ emission in upland soils.

• Clean Technology
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• v.17 no.2
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• pp.142-149
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• 2011

The adsorption and desorption behaviors of NO and $N_2O$ over two mixed oxide catalysts, AlCoPd (1/1/0.05) and AlCoFe (1/1/2), have been investigated for the lean $NO_x$ trap applications. The catalysts showed good adsorption capabilities for NO and $N_2O$ without needing oxidation step. The adsorption decreased a lot when they are co-adsorbed with oxygen. While NO kept high adsorbability and selectivity with respect to oxygen, those of $N_2O$ decreased sharply. From the TPD results, NO and $N_2O$ are considered to decompose into nitrogen and oxygen in the higher temperature range and the oxygen seems to be strongly attached to the catalysts even at high temperature.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.281-284
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• 2002

마 섬유는 흡습성이 좋고 건조가 빠르고, 습윤 시 강도가 증가되며 열전도율이 크고 통기성이 크며, 강도와 내열성이 천연 섬유 중 가장 우수하며 매끄러운 표면을 가지고있어서 광택과 방오성이 좋다. 그러나 세사방적이 어렵고 강연도가 지나치게 커서 의복소재로서 극히 제한적으로 사용되어왔으나, 최근에는 큰 강연도를 장점으로 활용하여 여름용 의복소재로 다시 각광받고 있다. 따라서 면, 레이온, 셀룰로오스계 섬유제품들에 대하여 마 제품과 유사한 효과를 낼 수 있는 다양한 의마가공법이 개발되어왔다[1,2]. (중략)

• Journal of the Korean Chemical Society
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• v.53 no.4
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• pp.466-470
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• 2009

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.4
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• pp.205-210
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• 2003

A 3-Transistor cell CMOS OTP ROM array using standard CMOS antifuse (AF) based on permanent breakdown of MOSFET gate oxide is proposed, fabricated and characterized. The proposed 3-T OTP cell for ROM array is composed of an nMOS AF, a high voltage (HV) blocking nMOS, and cell access transistor, all compatible with standard CMOS technology. The experimental results show that the proposed structure can be a viable technology option as a high density OTP ROM array for modern digital as well as analog circuits.

• Journal of the Korean Magnetics Society
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• v.10 no.4
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• pp.165-170
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• 2000

The purpose of this study is to investigate the effect of annealing conditions on physical and magnetic properties of Fe-Hf-N thin films. When the thin films were annealed in $N_2$ gas, a surface oxide layer, comprised of Fe$_2$O$_3$ and Fe$_3$O$_4$, was formed at the surface of the thin films and a Fe-Hf-O-N layer was also formed under this surface oxide layer. It was found that the thicknesses of the surface oxide layer and the Fe-Hf-O-N layer increased, as the annealing temperature increased. It was also found that if the thickness of the surface oxide layer was excluded in the property calculation, the soft magnetic properties of the annealed thin films were not much different from those of the as-deposited thin films. Therefore, it was suggested that the Fe-Hf-O-N layer formed under the surface oxide layer did not lose significantly the soft magnetic properties of the Fe-Hf-N films and the Fe-Hf-N films annealed in $N_2$gas showed the soft magnetic properties of the Fe-Hf-N and Fe-Hf-O-N multi-layers.