• Journal of Korea Water Resources Association
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• v.34 no.5
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• pp.521-532
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• 2001

The propagation patterns of nitrogen during rainfall events are unsteady and heterogeneous due to the characteristics of generation and transport mechanisms. A simulation of non point source pollution was performed using GRASS-AGNPS to examine efficient management methods for diffusive pollution. Digital Elevation Model(DEM) was prepared to estimate the impact of topography on the transport pattern of diffusive pollutant Hanjaechon watershed on the Kyungbook province was selected as a study ares. Water quality samples were collected and analyzed for the calibration of the model. A heuristic approach was employed to improve the model performance. The model could successfully produce spatial distributions of nitrogen. The constructed map-layers may help to decision makers to determine the best management practices.

• KSBB Journal
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• v.29 no.1
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• pp.72-80
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• 2014

CW-4Y was identified as Stenotrophomonas sp. by morphological and physiological characteristics, and phylogenetic analysis of its 16S rDNA gene sequence. Nitrogen removal by CW-4Y was analyzed in relation to the ammonium concentration, presence of organic carbon, carbon source, and carbon-to-nitrogen ratio (C/N). Stenotrophomonas CW-4Y has heterotrophic nitrification and aerobic denitrification abilities. Stenotrophomonas CW-4Y utilized only glucose as carbon sources, and heterotrophic nitrification and aerobic denitrification were observed regardless of the type of nitrogen source. The maximum ammonium removal rate of CW-4Y was 80 $mg-N{\cdot}L^{-1}{\cdot}d^{-1}$ and its denitrification rate of 192 $mg-N{\cdot}L^{-1}{\cdot}d^{-1}$ at $NO_3{^-}-N$ (about 280 ppm) in shake culture experiments at a C/N ratio of about 15 was about 30 times higher than those of other bacteria with the same ability.

• Journal of Plant Biology
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• v.14 no.3
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• pp.21-28
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• 1971

Dry matter production, leaf area growth and total nitrogen changes were studied in Glycine max. soybean communities, which were grown in sandy loam soils controlled to provide various moisture levels, i.e., 5-7%(level 1), 8-10%(level 2), 11-13%(level 3), 14-15%(lev디 4), 17-20%(level 5) and 22-24%(level 6). A summary of the results is shown. The maximum dry matter production of leaves, stems and nodules and the maximum leaf area per unit area were at level 5, but the maximum of root dry matter production was at level 4. Total nitrogen content of the soybean plant decreased with growth, but each level of soil moisture content also showed a little difference. Water content of the plant decreased with plant age and soil water deficiency, especially in roots and nodules. Nodule formation increased in proportion to soil moisture content. total nitrogen content of the soil on which the soybeans grew, increased from 0.23% before sowing to 0.30% at 100 days after sowing. It seems that soil water content acts as a linear factor in the elongation or dry weight increase of shoots and roots until increasing to level 5. Considering the pattern of plant growth through analysis of the shoot and root dry weight ratio, or the photosynthetic organ and non-photosynthetic organ dry weight ratio, the asymptote of plant growth at a high soil water content exceeded that at a low soil water content.

• Transactions on Electrical and Electronic Materials
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• v.9 no.5
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• pp.206-208
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• 2008

Implantation of metals and ceramics with ions of nitrogen and other species has improved surface properties such as friction, wear and corrosion in numerous industrial applications. In recent years, PCB drills tend to be more minimized increasingly as the electronics components have been more highly accumulated and minimized. Therefore nitrogen ion implantation was performed onto PCB drill (0.15 & 0.3 mm in diameter), in order to investigate mechanical properties of WC-Co cermets surface through Nano-indentation tests. PCB drill was implanted at energy of 70 keV, 90 keV, 120 keV and with the dose range of $1{\times}10^{17}$ and $5{\times}10^{17}\;ions/cm^{2}$. After ion implantation, WC-Co PCB drill bits was tested in actual operating situation to apply cutting tools industry and is concluded that the life time of nitrogen ion implanted PCB drills is one and a half times longer than the unimplanted.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.4
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• pp.63-70
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• 1997

The objectives of this study were to find out the optimum treatment conditions for removing nitrogen in a synthetic wastewater by using microorganisms immobilized with PVA-Freezing method. The samples used as influents to the laboratory scale treatment units were a synthetic wastewater. The experiments in this study were mainly directed to collect the data of nitrogen and organic matter removal efficiencies for the different hydraulic and internal recycle rates conditions, temperature and influent C/N ratios. The removal efficiencies of nitrogen and organic matters were investigated for the operating conditions of HRT 2~12hours, internal recycle rates 50~400%, temperatures $15{\sim}30^{\circ}C$ and C/N ratios 2.5~7.5. The adequate internal recycle rate for removing T-N and $BOD_5$ in the synthetic wastewater was found to be about 300% at the temperature of $30^{\circ}C$ when the ratio of carbon contents to the nitrogen (C/N) in the influent was around 5.5. Under these conditions, the final effluent concentrations of T-N and $BOD_5$ were 8.7 and 8.4 mg/l, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.154-159
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• 1995

In order to find out the effects of shading and nitrogen fertilizer on $NO_3^-$ accumulation in the edible parts of chinese cabbage, Cutivar, "Seoul", was cultivated in the pots under glasshouse condition with different rates of shading(0, 15, 30, 50, 75%) and nitrogen fertilization(recommended level, and double rate of recommended level). Leaf length, leaf width, yield (leaf weight), root width and root weight in the 15% shading rate showed the highest value, but decreased in the over 30% shading rates. The highest yield showed in the plot of the 15% shading rate with double rate application of recommended N level. High rate of shading increased the $NO_3^-$ accumulation, especially in midrib and outer leaf compared to leaf blade and inner leaf, respectively. The average $NO_3^-$ accumulation of edible parts of chinese cabbage are $4,872mg\;kg^{-1}$(outer midrib), $2,363mg\;kg^{-1}$(inner midrib), $1,405mg\;kg^{-1}$(outer leaf blade) and $727mg\;kg^{-1}$(inner leaf blade). $NO_3^-$ accumulation of outer midrib in the plots of double application of recommended N level were no difference between shading rate containing $5,000{\sim}6,000mg\;kg^{-1}$ $NO_3^-$, while in the plots of recommended N level it was increased by elevating shading rate. It was concluded that overuse of nitrogen fertiliration for chinese cabbage in glasshouse condition might lead to increase $NO_3^-$ accumulation. It could be advisable to cut out both the out leaf blade and outer midrib which might accumulate the high concentration of $NO_3^-$ before consumption.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1069-1075
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• 1999

The sterilization was attempted to improve the quality deterioration of soybean paste during its storage. For this experiment, soybean paste was sterilized at 80oC for 30 minutes and stored during 6 months at 15oC and 30oC, respectively. The total approximate composition contents were moisture 52.5%, crude protein 11.94%, crude fat 2.0%, amino nitrogen 413.3mg%, sodium chloride 11.61% and ash 15.5%. According to the increase of storage period, pH was decreased gradually because of the increase of organic acids by the metabolism of microorganisms and the acid accumulation by acid forming bacteria, but titratable acidity was increased during storage. Amino nitrogen was rapidly increased for the first one or two month storage period and maintained as the same level for the rest of them. Each amino acid contents of soybean paste, which were glutamic acid, tryptophan, proline, arginine, and aspartic acid, had much higher level than others. In color changes sterilized soybean paste(SSP) was much lower than that of raw ones(RSP). Hunter L and b values on the surface of soybean paste were decreased during storage, and the decreasing levels were higher at 30oC than at 15oC. Hunter a value, however, was increased a little in the initial storage, and thereafter it was decreased. Lactic acid bacteria, yeasts, and molds were disappeared completely by the sterilization. However, the bacteria of aerobes and anaerobes were not disappeared by this processing.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.15-25
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• 2012

Arundinaria munsuensis population were classified into Lespedeza maximowiczii dominant population and Spiraea prunifolia for. simpliciflora dominant population in the habitat of Jiri Mt. In the study sites, soil organic matter, total nitrogen, available phosphorous, exchangeable K, exchangeable Ca, exchangeable Mg contained, cation exchange capacity, and soil pH were ranged from 14.52~16.13%, 0.57~0.59%, 5.57~10.24 (mg/kg), 0.44~0.49 ($cmol^+/kg$), 0.62~0.92 ($cmol^+/kg$), 0.31~0.32 ($cmol^+/kg$), 28.26~32.44 ($cmol^+/kg$) and 4.33~4.48 respectively. DCCA ordination analysis showed that Lespedeza maximowiczii dominant population dwells where pH, exchangeable Ca and exchangeable Mg content are high and Spiraea prunifolia for. simpliciflora dominant population is placed where CEC, total nitrogen and organic matter content are high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.757-763
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• 2010

The qualities of Deodeok Doenjang including physicochemical characteristics and sensory properties were investigated over the following range of Deodeok levels: 5, 10, 15 and 20% (all w/w). The strains used in the manufacturing of Doenjang were Bacillus sp. B-3 and Aspergillus sp. M-9 with the highest enzyme activities like amylase and protease. In case of Deodeok Doenjangs prepared with Bacillus sp. B-3, the amino-type nitrogen of Doenjang containing 10% (w/w) Deodeok was produced more than others during fermentation for 40 days. Amino-type nitrogen produced in Deodeok Doenjang prepared with Aspergillus sp. M-9 was more than one of Deodeok Doenjangs with Bacillus sp. B-3 and a commercial Doenjang. When Deodeok content exceeded 15% (w/w), higher content resulted in lesser amino-type nitrogen production. The results showed that Deodeok had influenced growth of Bacillus sp. and Aspergillus sp. Sensory evaluation showed that Deodeok Doenjangs containing 10% (w/w) Deodeok and 1% (w/w) Bacillus sp. B-3 and containing 20% (w/w) Deodeok and 1% (w/w) Aspergillus sp. M-9 were superior to the other Doenjangs tested.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.385-391
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• 1996

To produce low salt fermented anchovy by an accelerated method with Asp. oryzae and Bacillus sp. koji and change of physicochemical properties in the fermentation during 60 days were examined. The contents of moisture, crude protein, ash and salinity of salted anchovy changed little during the fermentation with 62.5~63.8%, 12.0~14.1%, 12.8~13.8%, and 12.8~13.8%, respectively. but crude lipid decreased from 15.5~15.8% initially to 13.1~13.9% finally. The p during the fermentation decreased slowly until day 50 and increased afterwards. Acidity increased remarkably on day 10 and changed little afterwards. This increase in acidity was particularly observed in the use of Asp. oryzae koji. Amino nitrogen contents sharply increased until day 20 wit 686.0~756.0mg% and then increased slowly. Ammonia nitrogen contents in the use of koji increased until day 40 or 50 and decreased after that ; while those without koji steadily increased until day 60. The TBA values for all the samples reached the highest point on day from 20 to 30 and decreased afterwards. The TBA values and ammonia nitrogen contents were higher in Bacillus sp. koji than in Asp. oryzae koji. The alcohol contents of anchovy paste a little decreased during 10 days, increased slowly after that until day 50, and then decreased. The content of alcohol was higher in the use of koji than in the non koji.