• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.551-557
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• 2002

Carbon nitride films have been deposited on Si(100) substrate by a high voltage discharge plasma combined with laser ablation in a nitrogen atmosphere. The films were grown both with the without the presence of an assisting focused Nd:YAG laser ablation. The laser ablation of the graphite target leads to vapor plume plasma expending into th ambient nitrogen arc discharge area. X-ray photoelectron spectroscopy and Auger electron spectroscopy were used to identify the binding structure and the content of the nitrogen species in the deposited films. The nitrogen content of the films was found to increase drastically with an increase of nitrogen pressure. The surface morphology of the films was studied using a scanning electron microscopy. Data of infrared spectroscopy and x-ray photoelectron spectroscopy indicate the existence of carbon-nitrogen bonds in the films. The x-ray diffraction measurements have also been taken to characterize the crystal properties of the obtained films.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.1
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• pp.1-9
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• 1990

Tillering of orchardgrass during establishment year was considered as an important factor for ground cover and forage yield. Field experiment was conducted to examine seasonal fluctuation of tiller number in three cultivars of orchardgrass; Potomac, Hall-mark, and Sumas, after transplanting with five planting density. Also, effects of plant density and nitrogen application in cultivar, Potomac were studied on tillering, forage yield and various growth characteristics in pot experiment Tillers per plant decreased with increased density and showed seasonal variations. It increased up to July, decreased during summer months, and increased again from October. Sumas had less tillers than other cultivars, especially at high density. Tillers per unit area kept high during spring. After then, there was stady decrease through summer and remained constant without affecting by planting density. Nitrogen application increased tillers per unit area in Potomac up to 20kg/10a, but decreased its tiller production at 40kg/lOa. Maximum number of tiller was obtained in the combinations of 20kg application of nitrogen with higher density than 324 plant per square meter. Forage yield increased as nitrogen application increased, while it did not respond to plant density. Forage yield had high linear correlation between LAI, leaf number with a peak at 2800 culrns. For high forage yielding, it was suggested to obtain optimum number of tillers per unit area in early season as possible, applying of adequate amount of nitrogen with relative high density depend on cultural condition.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.1
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• pp.49-53
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• 1974

Varietal difference in nitrogen metabolism was investigated under water culture system with high (50 or 80ppm) and low (10 or 40 ppm) levels of nitrogen and with two-week minus nitrogen treatment at maximum tillering and heading stage using a leading local variety, Jinheung and high-yielding IR667 line (newly bred tropical variety). 1. In high nitrogen level Jinheung showed higher yield than IR667. vise versa in low nitrogen level. 2. Poor yield of IR667 at high nitrogen may be due to ammonium toxicity that was eliminated by minus nitrogen from culture solution. 3. IR667 was more sensitive to the change of nitrogen environment. 4. With high nitrogen medium Jinheung showed nigher nitrogen uptake and higher capacity of protein synthesis than IR667, and vise versa at low nitrogen medium. 5. From the above facts it could be concluded that Jinheung has higher metabolic adaptability for heavy nitrogen while IR667 has higher structural adaptability for heavy mitrogen and that better productive adaptability will be resulted in the combination of both characteristics.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.3
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• pp.33-36
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• 2023

Purpose: Since the food wastewater contains a high concentration of nitrogen, it is very important to find a way to efficiently remove it. Research design, data and methodology: A total of four experiments were conducted under different conditions to remove ammonia nitrogen present in the food wastewater. The experiment was designed by adding sodium hypochlorite to the raw food wastewater and varying conditions such as pH control, aeration/precipitation, and stirring. Results: The ammonia nitrogen removal rate in Experiment 1 was about 12% (sodium hypochlorite added), ammonia nitrogen increased about 4.7% in Experiment 2 (sodium hypochlorite added after aeration/precipitation in a bioreaction tank, stirring), and decreased about 52.5% (sodium hypochlorite added after controlling and stirring). Conclusions: When the concentration of sodium hypochlorite was high, ammonia nitrogen was best removed, and the pH was adjusted to 12, and sodium hypochlorite was added after stirring, and the removal was the second best. If the method of this study is further studied and developed, it can be basic data for ammonia nitrogen removal in the future.

• Analytical Science and Technology
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• v.35 no.6
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• pp.249-255
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• 2022

In this study, a new method for the analysis of high-purity nitrogen was developed. A gas chromatography-flame ionization detector (GC-FID) was used for purity analysis. Certified reference materials (CRMs) at a level of 3 µmol/mol of carbon monoxide (CO), carbon dioxide (CO₂), and methane (CH₄), which may exist in high-purity nitrogen, were prepared using the gravimetric method, and these CRMs were used for purity analysis. In this new method, ultra-high-purity and high-purity nitrogen were used as carrier gases. The impurities in high-purity nitrogen were quantitatively analyzed by comparing the differences in the area values of the GC chromatograms of the prepared CRMs. We purchased liquid nitrogen and three bottles of nitrogen gas, which were produced by three different manufacturers, using high-purity nitrogen. Furthermore, to validate the developed purity analysis method, the fraction of impurities in high-purity nitrogen was compared with the results of the typical purity analysis method. The comparison results were consistent within the expanded uncertainties (k = 2).

• Journal of the Korean Society for Heat Treatment
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• v.27 no.3
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• pp.121-126
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• 2014

High-nitrogen Fe-18Mn-18Cr-N austenitic steels with higher yield strength have been recently developed and used for generator retaining rings because they have non-magnetic, high strength, high ductility, and good corrosion resistance. In the present study, a high-nitrogen Fe-18Mn-18Cr-0.61N austenitic steel was fabricated and then tensile and Charpy impact tests were conducted on them in order to investigate the effect of cold working on the mechanical properties. Although the yield and tensile strengths usually increased with cold working, the ductility and impact toughness significantly decreased after cold working. On the other hand, the high-nitrogen austenitic steel exhibited a ductile-brittle transition due to unusual brittle fracture at low temperatures despite having a face-centered cubic structure. The ductile-brittle transition temperature obtained from Charpy impact tests could be remarkably increased by $60^{\circ}C$ after 20% cold working because of the enhanced cleavage-like brittle fracture.

• Membrane and Water Treatment
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• v.10 no.4
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• pp.265-275
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• 2019

This study aimed to develop a compact partial nitritation step by forming granules with high Ammonia-Oxidizing Bacteria (AOB) fraction using the Air-lift Granulation Reactor (AGR) and to evaluate the feasibility of treating reject water with high ammonium content by combination with the Anammox process. The partial nitritation using AGR was achieved at high nitrogen loading rate ($2.25{\pm}0.05kg\;N\;m-3\;d^{-1}$). The important factors for successful partial nitritation at high nitrogen loading rate were relatively high pH (7.5~8), resulting in high free ammonia concentration ($1{\sim}10mg\;FA\;L^{-1}$) and highly enriched AOB granules accounting for 25% of the total bacteria population in the reactor. After the establishment of stable partial nitritation, an effluent $NO_2{^-}-N/NH_4{^+}-N$ ratio of $1.2{\pm}0.05$ was achieved, which was then fed into the Anammox reactor. A high nitrogen removal rate of $2.0k\; N\;m^{-3}\;d^{-1}$ was successfully achieved in the Anammox reactor. By controlling the nitrogen loading rate at the partial nitritation using AGR, the influent concentration ratio ($NO_2{^-}-N/NH_4{^+}-N=1.2{\pm}0.05$) required for the Anammox was controlled, thereby minimizing the inhibition effect of residual nitrite.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.2
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• pp.123-134
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• 1997

The effects of cutting 6equency and nitrogen fertilization on feed values of reed canarygrass were investigated in uncultivated rice paddy and the attemp was made to estimate the economical and efficient levels of nitrogen fertilization for the increased production of nutrients in reed canarygrass. The results are summarized as follows; 1. Crude protein(CP) content was higher at 1st cut of all treatments(12.5% in 3 cutting 6equency; 19, 7% in 4 cutting frequency; 22.5% in 5 cutting kquency). However, Total Digestible Nutrients(TDN) and Relative Feed Value(RFV) in 3 and 4 cutting 6equencies were higher at 3rd cut(63.5%, 126.8) and 4th cut(65.7%, 146.4) respectively in which the contents of Neutral Detergent Fiber(NDF) and Acid Detergent Fiber(ADF) were lowest. In 5 cutting frequency, 1st cut showed the highest TDN and RFV as 70.5% and 232.4 respectively. 2. The level of nitrogen fertilization affected CP content of reed canarygrass. Nitrogen fertilization of 120kgl halcut showed high CP contents of 11.4, 14.7 and 16.5% in 3, 4 and 5 cutting eequency respectively. In 3 and 4 cutting frequency, TDN and RFV were highest with nitrogen fertilization of 90kg/ha/cut where NDF and ADF were lowest, however those in 5 cutting frequency were highest with nitrogen fertilization of 30kg/ha/cut. 3. The yields of CP varied according to the number of cutting frequency and those were 0.45~0.65 in 3 cutting hquency, 0.35~0.50 in 4 cutting frequency, and 0.19~0.67tond/ha in 5 cutting 6equency respectively and TDN was 2.09~3.60, 1.64~2.77 and 0.73~2.96tons/ha respectively. 4. The ratios between the yields of CP and TDN were 5.48, 4.60 and 4.34 in 3, 4 and 5 cutting 6equency respectively and it indicates lower ratio in result of higher number of cutting 6equency. 5. Higher nitrogen fertilization increased the yields of CP and TDN. The yields of CP were higher in 5 cutting frequency as 1.55~2.62tons/ha than of 3(1.20~1.91tons/ha) and 4 cutting frequency(1.35-2.23tons/ha). The yields of TDN were 6.31~9.93, 5.99~9.99 and 7.16~10.57tons/ha in 3, 4 and 5 cutting frequency respectively. 6. The levels of nitrogen fertilization for high production efficiency of crude protein(kg CPYkg N) was estimated as 113.4~302.5kg/ha and it resulted in 1.44~2.09ton/ha of CP yields. The levels of nitrogen fertilization for high production efficiency of dry matter was 199.2-361.3kgha in which nitrogen were fertilized below 400kg/ha and it resulted in 1.64~2.17ton/ha of CP yields. 7. The levels of nitrogen fertilization for high production efficiency of total digestible nutrients(kg TDNYkg N) were 149.9~294.1kg/ha in 3 and 4 cutting kequency and it resulted in 8.66~8.89ton/ha of TDN yileds. With the levels of nitrogen fertilization for high production efficiency of dry matter of 199.2~361.3kg/ha, TDN yields were high as 8.77~9.94ton/ha.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.43-48
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• 2003

The effect of rare earth(RE) at three difference levels of nitrogen on the growth and nitrate content of chicory (Cichorium intybus L.) were studied in terms of leaf size, fresh and dry weight increase, and chlorophyll and nitrate content grown in plastic pots within glasshouse. Leaf size was enlarged as the level of nitrogen applied was high, and leaf within, length, and thickness of leaf were increased by RE treatment showing significant difference at high nitrogen(N+1) plot. As the level of nitrogen applied was high, as fresh and dry weight per plant was increased significantly(p<0.05), and sprinkling cabbage with RE increased fresh and dry matter yield to 2∼12, 4∼6.2% more, respectively. Dry matter content of Chinese cabbage was increased by RE sprinkling. At all levels of nitrogen fertilized chlorophyll contents were increased by RE treatment. As the level of nitrogen was high, as the content of chlorophyll was highly increased by RE. Nitrate was accumulated more at high level of nitrogen application, but nitrate was decreased by RE application, 40% decrease at very high nitrogen plot(N+2). RE stimulated the growth of chicory with high chlorophyll content, and showed the possibility producing high quality agricultural products low in nitrate content.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.217-221
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• 2002

In the coarse grain HAZ adjacent to the fusion line, most of the TiN particles in conventional Ti added steel are dissolved and austenite grain growth is easily occupied during welding process. To avoid this difficulty, thermal stability of TiN particle is improved by increasing the nitrogen content in steel. In this study, the effect of high nitrogen TiN particle on preventing austenite grain growth in HAZ was investigated. Increased thermal stability of TiN particle is helpful for preventing the austenite grain growth by pinning effect. High nitrogen TiN particle in simulated HAZ were not dissolved even at high temperature such as 1400 C and prevented the austenite grain growth in simulated HAZ. Owing to small austenite grain size in HAZ the width of coarse grain HAZ in high nitrogen TiN steel was decreased to 1/10 of conventional TiN steel. Even high heat input welding, the microstructure of coarse grain HAZ consisted of fine polygonal ferrite and pearlite and toughness of coarse grain HAZ was significantly improved.