• The Korean Journal of Ceramics
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• v.4 no.3
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• pp.222-226
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• 1998

$Cu_3N$ film deposited on silicon oxide substrate by r.f. reactive sputtering technique. Synthesis and properties of copper nitride film were investigated for its possible application to Cu metallization as adhesive interlayer between copper and $SiO_2. Cu_3N$ film was synthesized at the substrate temperature ranging from $100^{\circ}C$ to $200^{\circ}C$ and at nitrogen gas ratio above $X_{N2}=0.4. Cu_3N, CuN_x$, and FGM-structured $Cu/CuN_x$ films prepared in this work passed Scotch-tape test and showed improved adhesion property to silicon oxide substrate compared with Cu film. Electrical resistivity of copper nitride film had a dependency on its lattice constant and was ranged from 10-7 to 10-1 $\Omega$cm. Copper nitride film was, however, unstable when it was annealed at the temperature above $400^{\circ}C$.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.178-185
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• 1998

To reduce the particulate matter and nitrogen oxides from diesel engine, many studies are proceeding and being accomplished practically. In this situation CNG engine has important meaning both as a clean fuel and an alternative energy. In order to present the direction and application of CNG, we simulated various operating conditions, that is, spark timing, compression ratio and fuel composition etc. Thus we try to understand how those affect performance and exhaust characteristics. The simulation program results found that the optimum combustion start angle was 21$^{\circ}$ at 1800rpm and fuel composition affects performance and emissions, also we could understand the formation of emission as crank angle is changed.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.9
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• pp.908-912
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• 1991

YBaCuO oxide superconductor-shows superconductive at Liquid Nitrogen temperature-must be preparate wire or thin film form for utility. The wiring is possible with heat treatment after appropriate mixture of polymeric binder and YBaCuO oxide superconductor has fabricated. This study, analyzed the characteristics of fabricated superconductor and extruded wire after application to each of a mixed at different rate in the superconductor and compared with an original pure sample. From the result, we knew that the binder component influences superconducting characteristics. The best condition for superconductivity occurred at a criticla temperature of 86.4K (8:2 rate) and at a critical current density of 100.27A/cmy with a binder packing ratio of about 20~25 percent.

• Membrane and Water Treatment
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• v.4 no.1
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• pp.11-25
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• 2013

Emulsion liquid membrane (ELM) process suffers from emulsion instability problem. So far, emulsion produced by mechanical methods such as stirrer and homogenizer has big size and high emulsion breakage. This paper discussed the application of emulsion produced by sonicator to extract cadmium in a batch ELM system. The emulsions consist of N,N-Dioctyl-1-octanamine (trioctylamine/TOA), nitrogen trihydride (ammonia/NH4OH), sorbitan monooleate (Span 80), and kerosene as carrier, stripping solution, emulsifying agent, and organic diluent, respectively. Effects of comprehensive parameters on extraction efficiency of Cd(II) such as emulsification time, extraction time, stirring speed, surfactant concentration, initial feed phase concentration, carrier concentration, volume ratio of the emulsion to feed phase, and pH of initial feed phase were evaluated. The results showed that extraction efficiencies of Cd(II) greater than 98% could be obtained under the following conditions: 15 minutes of emulsification time, 4 wt.% of Span 80 concentration, 4 wt.% of TOA concentration, 15 minutes of extraction time, 250 rpm of stirring speed, 100 ppm of initial feed concentration, volume ratio of emulsion to feed phase of 1:5, and initial feed pH of 1.53.

• Environmental Engineering Research
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• v.23 no.4
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• pp.364-373
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• 2018

The present study assessed the efficient removal of nutrients and Chlorophyll-a (Chl-a) by using methyl esterified sericite (MES) and pine needle extracts (PNE), a low cost and abundant green hybrid material from nature. For this purpose, the optimal conditions were investigated, such as the pH, temperature, MES and PNE ratio, and MES-PNE dose. In addition, a Microcystis aeruginosa control using MES-PNE was also analyzed with various inhibition models. The removal of the nutrient and Chl-a onto MES-PNE was optimized for over 95% removal as follows: 2-2.5 for the MES-PNE ratio, 7-8 pH and a $22-25^{\circ}C$ temperature. In this respect, approximately 1.52-2.20 g/L of MES-PNE was required to remove each 1 g of dry weight/L of Chl-a. Total phosphorus (TP) has a greater influence on the increase in Chl-a than total nitrogen (TN) according to the correlation between TN, TP and Chl-a. Moreover, the Luong model was the best model for fitting the biodegradation kinetics data from Chl-a on MES-PNE from lake water. The novel hybrid material MES-PNE was very effective at removing TN, TP and Chl-a from the lake and can be applied in the field.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.428-434
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• 2008

The objective of this study is to investigate the effect of the level of $CO_2$ (370 and $650{\mu}mol\;mol^{-1}$) and temperature (ambient and ambient+$5^{\circ}C$) on tomato growth and fruit characteristics as affected by the application rate of N-fertilizer (68 and $204\;N\;kg\;ha^{-1}$), for the purpose of evaluating the influence of elevated $CO_2$ and temperature on tomato crop. The elevated atmospheric $CO_2$ and temperature increased the plant height and stem diameter for tomato crop, while the differences among the nitrogen(N) application rates were not significantly different. Under the elevated $CO_2$, temperature, and a higher N application rate, the biomass of aerial part increased. The fruit yield showed the same result as the biomass except for the elevated temperature. The elevated temperature made the size of fruit move toward the small, but the elevated $CO_2$ and the application of N-fertilizer were vice versa. The sugar content and pH of fruit juice were affected by nitrogen application rate, but not by the elevated $CO_2$ and temperature. These results showed that both the elevated $CO_2$ and temperature stimulated the vegetative growth of aerial parts for tomato, but each effects on the yield of fruit showed an opposite result between the elevated temperature and $CO_2$. In conclusion, the elevated $CO_2$ increased tomato yield and the ratio of large size of fruit, but the elevated temperature did not. Therefore, to secure the productivity of tomato as nowadays in future environment, it will need to develop new breeder as high temperature-tolerable tomato species or new type of cropping systems.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.3
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• pp.181-188
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• 2007

Objective of this research was to identify by-product composting impacts on paddy soil properties and rice yield. Research was conducted in Iksan (soil was identified as a Jeonbug series) located in Honam plain area from 2001 to 2004. Composts, such as cow manure sawdust compost(CMSC), Chicken manure sawdust compost(ChMSC) and Pig manure sawdust compost(PMSC) were treated in the reseach plots for every, 2, and 3 year term. Some physical properties, such as, soil hardness, and bulk density tended to decrease with application of compost and decreased in order of CMSC, ChMSC, and PMSC, while surface soil depth and porosity were increased in order of CMSC, PMSC, and ChMSC. Some chemical soil properties, such as organic matter, available phosphorus, available silicate, and exchangeable cations were increased with application of compost and every year application plots. Nitrogen uptake was higher in order of CMSC, ChMSC, SF, and PMSC. Nitrogen use efficiency was higher in order of CMSC, ChMSC, SF, and PMSC. Rice yields was increased in all application plot of CMSC, in every other year application plot ChMSC and PMSC compared with SF($5.07Mg\;ha^{-1}$). Also average rice yield on years were increased in all application plot of CMSC and in every other year application plot ChMSC, while decreased in all application plot of PMSC compared with SF($5.27Mg\;ha^{-1}$). Head rice ratio and perfect grain ratio on hulled rice was high in all application plot of PMSC and in every year, in every other year app lication plot of ChMSC while its lowered percentage of 10~13 caused by application of CMSC compared with SF.

• Applied Biological Chemistry
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• v.11
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• pp.173-184
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• 1969

To elucidate the effect of Amo-1618(4-hydroxyl-5-isopropyl-2-methlphenyl trimethyl ammonium chloride, 1-piperidine carboxylate) known as a kind of growth retardant, on the growth, grain yield, increasing the efficiency of nitrogen fertilizer, behavior of mineral nutritions and the rate of phosphorus utilization, this experiment was conducted pot culture method in a vinyl house. Two nitrogen level, namely, practical nitrogen level(1 N) and three times nitrogen level(3 N) was made and labelled double-calcium-superphosphate $Ca(H_2P^{32}O_4)_2.\;2H_2O)$ as a source of radioactive phosphorus(P-32) was employed $80\;{\mu}c/pot$, respectively. Rice seedlings, variety 'Suwon No. 82', was transplanted to a 1/50,000 a china pot on June 13 in 1968. For treatment, at early stage of tillering, 10,000 ppm solution of Amo-1618 was foliar sprayed only one time. The Duncan's new mutiple-range test was adopted for statistical analysis evaluating experimental data at 5% level significance. The results obtained may be summarized as follows; 1) No significant difference was found among the treatments in plant height, but in plot of Amo-1618 treatment and 3 N level, number of tillers was significantly increased than that of others. 2) Weight of 10,000 kernels and seed-setting rate was also remarkably increased in same treatment above. 3) Grain yield per pot was significantly increased in Amo-1618 and 3 N level application. This results seemed to be due to the increased the factors on the yield. 4) Contents of nitrogen and phosphorus per cent in the grain was likewise increased in Amo-1618 and 3 N application. There is, however, no difference among treatments in the content of nitrogen and phosphorus in the leaves and culms of rice plants. 5) On the other hand, the contents of potassium and magnesium, no distinctly tendeny showed among treatments. 6) The rate of phosphorus utilization was significantly increased in the plot of Amo-1618 and 3 N application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.52-57
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• 2006

This research was carried out to determine the effect of controlling nitrogen application on tiller development, yield, and quality of rice under scanty or excess seedling stands in direct-seeded rice on flooded soil surface. Seedling stand was set to 3 levels: scanty $(60/m^2)$, optimum $(120/m^2)$, and excess $(200/m^2)$. In the scanty plot, additional 4 kg/10a nitrogen was applied at the 3rd leaf stage to promote tiller development. On the other hand, applying 3.3 kg/10a nitrogen at 5th leaf stage in the excess plot was omitted to suppress tillering. Maximum numbers of tillers per plant were 15.2 and 8.6 in scanty and excess plots, respectively, as compared with 9.8 in optimum plot. Productive tiller rate decreased with the increase in number of seedling stands. Regardless of seedling density, the first tiller developed on the 3rd node of rice stem from the bottom. The primary tillers developed at 3, 4, 5, 6, 7 nodes in scanty plot, 3, 4, 5 nodes in optimum plot, and 3, 4 nodes in excess plot. The secondary tillers developed only in some portion of plants in scanty and optimum plots. The order of tiller emergence was negatively correlated to stem length, panicle length, non-productive tiller number, grain number per panicle, and fertility in scanty plot, and to perfect grain ratio in excess plot. In the optimum plot, however, the order of tiller emergence was not correlated to any of the mentioned characteristics. The perfect grain ratio of scanty plot was the highest because green-kerneled rice was a very small portion in the primary tillers as compared with those of optimum and excess plots. Yield indexes of scanty and excess plots were 99%, and 97%, respectively, of the yield (494 kg/10a) in optimum plot. In conclusion, when seedling stands are not at optimum level, rice yield and quality similar to optimum planting density level can be obtained by means of controlling nitrogen application.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.40-43
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• 1990

Study was conducted to investigate the optimum amount of nitrogen fertilizer for the green forage production of Italian ryegrass at the paddy field after rice harvesting in southern part of Korea in 1987 and 1988. Effects of three levels of nitrogen fertilizer application (15, 30 and 45 kg N/10a) on the green yield and nitrate content of green forage at three cutting times (April 30, May 20 and June 10) were examined in 1988. The results were as follows. 1. Yield of green forage at all cutting times increased in order of 45 > 30 > 15 kg N/10a, and it increased about 14 percent in the 45 kg N/10a and decreased about 35 percent in the 15 kg N/10a compared with the 30 kg N/10a. 2. Nitrate content in the green forage at all cutting times was high with increasing amount of nitrogen fertilizer and with decreasing ratio of K/(Ca+Mg) in green forage. The nitrate content at the second and the third cutting times in the 45 kg N/10a might be outrunned the tentative limitation for cattle. 3. Maximum amount of nitrogen fertilizer was 48 kg/10a for total green forage production, but it was 38 kg/10a near at cattle's harmful limit of nitrate content in green forage.