• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.94-97
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• 1997

We investigated the sheet resistance properties of tungsten nitride thin films deposited by RF and DC sputtering system. It deposited at various conditions that determine the sheet resistance. The properties of the sheet resistance of these films were measured under various conditions. Sheet resistance analysed under the flow rate of the argon gas and contents of nitrogen from nitrogen-argon gas mixtures. We found that these sheet resistance were largely depend on the temperature of substrate, gas flow rate and RF power. Very high and low sheet resistance of tungsten films obtained by DC sputtering. As the increase of contents of nitrogen gas obtained from nitrogen-argon gas mixture, tungsten nitride thin films deposited by the reactive DC sputtering and the sheet resistance of these films were increased.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1009-1016
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• 2012

The purpose of this study was to determine the effects of organic fertilizers on soil properties and growth and quality of melon. Organic fertilizer was applied in soil at the rate of 0, 0.5, 1, 2N according to Rural Development Administration guideline in Korea. The fertilizer had no effects on plant growth-rate parameters, including plant height, leaf number, and leaf size. There were minor effects on the fruit quality parameters such as fruit weight, fruit length, fruit width, placenta and seed weights, sugar content, and starch content. Ascorbic acid level was decreased as fertilizer level was increased. The level of nitrate in groundwater increased with increased levels of N.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.128-138
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• 1998

This study was focused to find how each factors effect on the biological nitrification in wastewater treatment under high ammonia nitrogen concentration. Batch reactors in aerobic conditions were used to test the treatment efficiency of mixed liquor, nightsoil and piggery wastewater. The results are summeried as follows; Initial ammonia nitrogen concentration and pH were the direct influencing factors of nitrite build-up. More than 250 mg NH$_{4}$$^{+}$ - N/L in initial concentration built up nitrite and then the inhibition rate to Nitrobacter was above 70 percentage. And maximum nitritation rate was showed at pH 8.3 and nitrification could be completely achieved by pH control. Temperature and dissolved oxygen were the indirect influencing factors of nitrite build-up. These were a great effect on the activity of nitrifying microbes and ammonia nitrogen removal. Maximum nitritation rate was showed at 30 $\circ $C. The effect of DO concentration was negligible at more than 3 mg/L.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.353-358
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• 2005

The present study investigated the feces production rate and fecal nitrogen production ratio of abalone, Haliotis discus hannai fed seaweed, Undaria pinnatifida. The abalone, with shell lengths of 3 cm, 5 cm, and 7 cm, were tested at temperatures of $12^{\circ}C$, $16^{\circ}C$, and $20^{\circ}C$ in a semi-recirculating aquaculture system. Under the given experimental conditions, the weight specific feces production rate (FPw) of the abalone increased with the decrease of shell length and the increase of temperature. The relationship of the FPw was. $FPw=-3.092+206.573/T - 1916.8/T^2+0.141L -0.037L^2(r^2=0.9412)$. In addition the abalone produced 17.8-22.5% of fecal material against ingested seaweed, Undaria pinnatifida, and $18.4-22.4\%$ of nitrogen ingested total nitrogen.

• KSBB Journal
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• v.13 no.4
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• pp.391-398
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• 1998

The effect of culture medium copper availability on the specific growth rate(${\mu}$) and carbon conversion efficiency (CCE) was sutided for an obligatory methanotroph Methylosinus trichosporium OB3b under various combinations of carbon and nitrogen sources. Methane or methanol was used as a carbon source, and nitrate or ammonium was used as a nitrogen source. Medium copper availability determined the intracellular location or kind of methane monooxygenase (MMO), cell-membrane (particulate or pMMO) when copper was present and cytoplasm (soluble or sMMO) when copper was deficient. When methane was used as a carbon source, copper-containing medium exhibited higher ${\mu}$ and CCE than copper-free medium regardless of the kind of nitrogen source. When methanol was used as a carbon source, however, the effect of copper disappeared. Ammonium gave the higher ${\mu}$ and CCE than nitrate for both methane and methanol. Those observation suggest that there exist an important difference in energy utilization efficiency for methane assimilation between sMMO and pMMO.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.2
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• pp.113-122
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• 1998

This experiment was conducted to establish the cultural method of triticale(Triticum Secalotriticum Saratoviense Meister) as a whole crop silage by evaluating the effect of seeding date and nitrogen fertilization rate on forage yields and feeding value. Heading date, flowering date, and the dough stage of development came significantly earlier as triticale was seeded earlier. Soilage, dry matter yields and percent dry matter significantly varied with seeding dates and crude ash, NFE and TDN. However, TDN yield was significantly reduced by delayed seeding. Macromineral contents were not affected by seeding date. Soilage, dry matter yield, and percent dry matter significantly increased as nitrogen fertilization rate increased. The contents of crude protein, crude fat, crude ash, NFE, TDN and TDN yield also significantly increased. In contrast, crude fiber content of triticale decreased with increasing N fertilization rate.

• Korean Journal of Agricultural Science
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• v.45 no.1
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• pp.9-18
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• 2018

This study was done to determine the effect of additional nitrogen fertilization on the yield and quality of the Korean wheat cultivars Keumkang, Jokyoung, Baegjoong, Sooan, Uri and Goso. Different levels of nitrogen applications (109, 82, 55, 41, and 27 kg/ha) were applied to six cultivars. The results show that the yield and protein contents were increased in all tested cultivars. The grain yields of the cultivars Keumkang, Jokyoung, Baegjoong and Sooan were greatly increased in the case of double fertilization treatments. Moreover, Uri and Goso had greatly increased yields by the additional fertilization at a 50% rate compared with korea wheat standard fertilization rate. A significantly higher yield was observed in Uri. Baegjoong was the highest yielding cultivar among the tested cultivars with the additional nitrogen fertilization. As the fertilization was increased up to double the fertilization treatment, the yield of Baegjoong also showed a constant increase. Positive correlations were found between the nitrogen fertilizer application levels and the protein contents of the grain in all the cultivars except for Uri, and among these, Jokyoung had a most significant correlation between the nitrogen fertilizer application level and the increase in its protein contents. Keumkang had the highest protein contents and highest increase in the protein content change according to the amount of nitrogen application. However, amylose, damaged starch and ash contents were not significantly changed by the different levels of nitrogen applications.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.4
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• pp.429-437
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• 2007

This study aims to develop a sulfur-using denitrification process which is possible a renovation to advanced treatment plant submerging a simple module in activated sludge aeration tank. At first, the impact factor of sulfur-using denitrification was appreciated by the batch test. Secondly, reflecting a dissolved oxygen effect of sulfur-using denitrification that was confirmed by the batch test, in a continuous nitrification/sulfur-using denitrification, high-rate nitrogen removal reaction was induced at optimum condition controlling DO concentration according to phases. Also, inside and outside of sulfur-using denitrification module was covered with microfilter and the module was considered as an alternative of clarifier. Result of batch test for sulfur-using denitrification, $NO_2{^-}N$ was lower for consumption of alkalinity and sulfur than that of $NO_3{^-}-N$. These results revealed the accordance of theoretical prediction. In continuous nitrification/sulfur-using denitrification experiment, actual wastewater was used as a influent, and influent nitrogen loading rates were increased 0.04, 0.07, 0.11, $0.14kg\;N/m^3-day$ by changing hydraulic retention times. At this time, nitrogen loading rates of packed sulfur were increased 0.23, 0.46, 0.69, $0.93kg\;N/m^3-day$. As a result, nitrification efficiency was about 100% and denitrification efficiency was 93, 81, 79, 72%. Accordingly, nitrogen removal was a high-rate. Also the module of sulfur-using denitrification covered with microfilter did not make a fouling phenomena according to increased flux. And the module was achieved effluent suspended solids of below 10 mg/L without a clarifier. In conclusion, it is possible a renovation to advanced treatment plant submerging a simple module packed sulfur in activated sludge aeration tank of traditional facilities. And the plant used the module packed sulfur is expected as a effective facilities of high-rate and the smallest.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.273-279
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• 2008

Space separation method that use independent reactor for nitrification and other reactor for denitrification has been commonly used for biological nitrogen removal process like $A^2O$ process. However, this method needs large space and complicate pipelines and time separation method such as SBR process have a difficulty in continuous treatment. Thus biological nitrogen removal process which is capable of continuous treatment, easy opeation and space saving is urgently required. In this research, submerged moving media was used for a biofilm process and suspended sludge was used for biological nitrogen removal at the same time. In particular DO environment by controlling air flow rate was investigated for simultaneous nitrification/denitrification. Total nitrogen removal in aeration rate more than $67L/min{\cdot}m^3$ showed 51~53% and rose to 65%, 70% and 78% in $50L/min{\cdot}m^3$, $58L/min{\cdot}m^3$ and $25L/min{\cdot}m^3$ respectively. Total phosphorus removal was very low about 10~20% more than $67L/min{\cdot}m^3$ aeration rates. But total phosphorus removal roses when reduces aeration rate by $58L/min{\cdot}m^3$ low and it showed total phosphorus removal of 72% in aeration rate $25L/min{\cdot}m^3$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.69-77
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• 2019

In this study, we evaluated the mechanical properties and nitrogen oxides removal characteristics according to the type and incorporation rate of the photocatalyst and investigated the method of separated placement for the production of economical and efficient photocatalyst concrete. As a result, when the photocatalyst incorporation rate was 5%, the highest compressive strength and elastic modulus were measured. As a result of evaluating the nitrogen oxides removal performance by the photocatalytic reaction, as the photocatalyst incorporation rate increased, the nitrogen oxide removal rate increased. At this time, the nitrogen oxides removal performance of photocatalyst P-25 was better than the NP-A. In consideration of economic efficiency, we have provided a method of separated placement for casting a constant thickness of concrete surface with photocatalyst concrete and evaluated the integrated performance at this time. As a result, it appears to be equal to or higher than mechanical performance and durability performance as compared with Plain, and it is judged that the integrated behavior is satisfied.