• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.29.2-29.2
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• 2010

We present elemental abundances of 412 blue compact dwarf galaxies (BCDs) at z=0.2~0.5 using the Sloan Digital Sky Survey (SDSS) DR7. The gas-phase nitrogen to oxygen abundance ratios (N/O) of sample galaxies increase as the oxygen to hydrogen abundance ratios (O/H) decrease. This indicates that the nitrogen is more enriched than the oxygen. We found that there is a noticeable distinction between the merger candidates and the isolated galaxies. Merging candidates show more enrichment of nitrogen abundance compared to isolated galaxies. On the other hand, neon and oxygen abundances for merging candidates are slightly lower than the isolated systems. We discuss the main cause of these trends with internal mixing and mass loss by fast rotation of young massive stars. We also discuss the environmental effect to the relation between specific star formation rate and galaxy mass.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.19-21
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• 2000

We are developing portable type HTS magnet system cooled by solid nitrogen. This system have recooling and recharging capabilities. In this paper, we report preliminary test results obtained from the experimental solid nitrogen system and pancake magnet would with Bi-2223/Ag tapes, respectively. The operation period was sensitively dependent on the vacuum rate n the cryostat, size of SUS tube for flowing N_{2}$, and liquid nitrogen to cool the cryostat. The fabricated coil I_{c}$was 75 A at 20 K in self field.

• Journal of environmental and Sanitary engineering
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• v.13 no.1
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• pp.26-31
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• 1998

Removal of nitrogen and phosphate in wastewater is concerned to important for the prevention of eutrophication in receiving water and lake. Conventional activated sludge system designed for organics removal can be retrofitted only by modification of aeration basin to maintain anaerobic and aerobic state. Biological nutrient removal processes(BNR) such as Bardenpho, A$^{2}$/O, UCT, VIP were generally used for the treatment of wastewater. However these BNR processes used in large scale WWTP were not suitable in small scale WWTP(i.e., package type WWTP) due to relatively large fluctuation of flow rate and concentration of pollutants. The purpose of this research was to develop the compact, effective and economical package type WWTP for the removals of carbon and nitrogen in small scale wastewater. Intermittently aerated activated sludge system (IADFAS) were investigated for removal of nitrogen in both domestic wastewater, Bardenpho process was also evaluated. Nitrogen removal of IAAS, IADFAS, Bardenpho were 75, 77 and 67%, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.191-198
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• 1984

This experiment was conducted to determine Gibberellin content in tobacco leaves at different growth stages in relation to nitrogen levels applied. Some of the results obtained can be summarized as follows: 1. The content of Gibberellin showed an increasing tendency as the levels of nitrogen increased. 2. The highest content of Gibberellin was observed at 60 days after transplanting, showing much higher than those of 30 and 90 days after transplanting. 3. The content of Gibberellin at various growth stages under different nitrogen levels ranged from 0.2490 ng to 10.9308 ng per IKg of fresh leaf weight of Burley 21. 4.The kinds of Gibberellin present in tobacco leaf appeared to be Gibberellinl ,9,19 and 20.

• Journal of Plant Biology
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• v.27 no.4
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• pp.253-261
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• 1984

Leaf discs isolated from the pea seedling grown in nutrient solution containing 5mM ammonia or nitrate exhibited a half level of photorespiration as compared with the nitrogen free control. The manifestation of the ammonia effect appeared somewhat earlier than that of nitrate effect, but this difference subsided as the culture periods was extended. The total amount of ${CO}_2$ fixed by leaves from nitrogen-supplemented seedlings showed approximately 1.5 fold increase over the control with the ammonia effect being manifested earlier than the nitrate effect. The activities of peroxisomal serine: glyoxylate aminotransferase were always higher with ammonia than nitrate, the two types of nitrogen source, however, had similar effect on conversion rate of glyoxylate into glycine. These results indicate that exogenous ammonia does not act directly as an effector of this aminotransferase in vivo. But changes in the level of the pool size of glycine and serine, both of which are the intermediates of photorespiratory process, suggest that exogenous ammonia inhibit the transformation of serine from glycine metabolically.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.326-332
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• 2018

In this study,the result shows that polyvinyl alcohol-sodium alginate (PVA-SA) gel bead crosslinked with sodium sulfate are better among the different methods by comparing the relative mechanical strength, mechanical strength swelling and expansion coefficient of beads in water. Subsequently, anammox biomass entrapment by PVA-SA gel was introduced into continuous stirred tank reactor (CSTR). After 24 operation days, the nitrogen removal efficiency achieved 60%, while the nitrogen loading rate (NLR) was $0.14kgN/m^3/d$ and the experiment data indicated that PVA-SA gel bead crosslinked with sodium sulfate can be used to initiate anammox process. Furthermore, it is an alternative for culturing anammox in a long-term operation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.169-176
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• 2013

Preharvest sprouting seriously reduces milling and baking quality of hard winter wheat (Triticum aestivum L.) grain. To determine the effect of nitrogen fertilizer application on decreasing of preharvest sprouting, several levels of N-fertilization were conducted in two winter wheat cv. Keumkang and Jokyung, grown in Iksan. Nitrogen fertilization is used to increase grain yield and protein content. Grain yield increased at 108kg/ha (50% increased nitrogen to the standard) application and decreased as more nitrogen was applied. There was a linear increase in grain protein contents with increasing level of nitrogen application. Germination rate, germination index and ABA sensitivity were gradually reduced by increasing of nitrogen application level. Preharvest sprouting showed a significantly correlation to germination rate but could not be correlated to protein content and falling number. A significant positive correlation was detected between preharvest sprouting and different additional nitrogen fertilizer levels.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.44-50
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• 1981

This experiments was carried out to evaluate the effect of nitrogen retention on different levels of crude protein intake according to live weight, and the crude protein and urea content in serum of the Korean native goat. The results obtained are as follows: 1. When the female goat at 8 months age (14kg) had taken nitrogen free diet, the content of endogenous urinary nitrogen was 1.29g and endogenous fecal nitrogen was 1.27g per day. Therefore, the goat needs minimum level of crude protein per day. 2. When the thermometer checked below-$10^{\circ}C$, the nitrogen retention rate showed minus reaction in spite of 20% crude protein level. This suggested that the low temperature was consumed higher energy to maintain the body. 3. The nitrogen retention rate of the pregnant female goat of 20kg live weight, however, decreased as compared with the growing goat and was 17~20%. 4. According to the levels of crude protein were lower, crude protein and urinary nitrogen contents in serum were greatly decreased.

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.260-265
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• 2005

Indoor air quality might be affected by source strength of indoor pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate the source strength and deposition constant by application of multiple measurements. For the total duration of 60 days, indoor and outdoor $NO_2$ concentrations every 3 days were measured in 30 houses in Seoul, Asan and Daegu. Using a compartment model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the source strength and deposition constant were estimated. Natural ventilation was $1.80{\pm}0.42\;ACH,\;1.11{\pm}0.50\;ACH,\;0.92{\pm}0.26\;ACH$ in Seoul, Asan and Daegu, respectively. Calculated deposition constant(K) and source strength of $NO_2,$ in this study were $0.98{\pm}0.28\;hr^{1}\;and\;16.28{\pm}7.47\;ppb/h,$ respectively.

• Journal of Life Science
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• v.13 no.1
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• pp.47-53
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• 2003

The purpose of this study is to improve the system for biological nitrogen oxidizing process in sewage and wastewater. A bacterium having high abilities to oxidize of nitrogen was one of the possessed on Lab. The strain was identified to Bacillus sp. A8-8, based on the physiological and biochemical properties. And the strain has ability degradation crude oil. In comparison with oxidizing rates with changing initial pH and temperature, the strain Bacillus sp. A8-8 was nitrogen oxidizing ability and growth rate on the various of pH, temperature. oxidizing rates of the strain in sewage and wastewater were about 48% and 62%, respectively. The nitrogen oxidizing rate was increased in proportion to the initial concentration of glucose. The microorganism, Bacillus sp. A8-8, immobilized in ceramic carrier were evaluated for the oxidation of ammonia in culture media.