• Journal of Environmental Science International
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• v.4 no.3
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• pp.87-87
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• 1995

This study was investigated with denitrification of wastewater containing nitrate using upflow sludge blanket process. Contents of this study were the nitrogen gas Production, relationship between HRT and COD/$NO_3^--N$ ratio in case of various hydrogen donor addition, relationship between nitrate loading rate and various hydrogen donor addition.

• Journal of Environmental Science International
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• v.4 no.3
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• pp.239-247
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• 1995

This study was investigated with denitrification of wastewater containing nitrate using upflow sludge blanket process. Contents of this study were the nitrogen gas Production, relationship between HRT and COD/$NO_3^--N$ ratio in case of various hydrogen donor addition, relationship between nitrate loading rate and various hydrogen donor addition.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.4
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• pp.120-128
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• 2001

Pollution sources and their environmental contributions were investigated to select the best management practices for the effective control of water quality. The nitrogen isotope mass ratio was determined to estimate the nitrate sources and their contribution. Sampling sites were chosen by calculating effluent loads at each watershed. Two liters each of the surface water samples were collected from four sites at Bokha river and two sites and Gwanri river. They were sequentially prepared through distillation method and analyzed using an isotope ratio mass spectrometer(IsoPrime EA). As revealed by the experimental values obtained the mass ratio values ($\delta$$^{5}$ N) of watersheds with a large amount of nonpoint sources were less than +5 an indication that the samples were influenced by chemical fertilizers. However watersheds with large amount of point sources were influenced not only by chemical fertilizers but also by animal and municipal wastes. The mass ratio values of samples generally decreased during rainy days. But during dry days the mass ratio values well-reflected the nitrate sources and the condition of watersheds. Through this study the nitrogen isotope mass ratio has been found to be useful for estimating nitrate sources and their contribution to the rural watersheds.

• Journal of Plant Biology
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• v.30 no.3
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• pp.205-213
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• 1987

Soybean, inoculated with effective Rhizobium japonicum 110, were grown by sand culture with nutrient solution containing either of 0, 1, 3, 10 or 30mM NO3-/l, and analyzed growth characteristics, NR activity, N2-fixation activity, and changes of ureide contents during the growing period. The amount of nodule formation decreased abruptly by nitrate treatment, the maximum nodule dry weight was 1.59, 1.05, 0.78, 0.09 and 0.008 g plant-1, respectively for each treatment on the 98th day. Specfic activity of N2-fixation showed the maximum rates of 140, 101, 37, 5 and 2.2 nM dw.mg-1.hr-1, respectively for each treatment in the earlier growth period. The maximum acetylene reduction activity on the 98th day after sowing was 81.5, 35.3, 14.3, 0.1 and 0.0045 $\mu$M C2H4 plant-1.hr-1, respectively for 0, 1, 3, 10 and 30 mM of NO3- gradients. Nitrate reduction activity increased along with nitrate gradients, and decreased abruptly with age. Relative abundance of ureides in plant organs was high in reproductive growth, and showed the maximum value in fully symbiotic dependent plant. Relative abundance of ureides in stem is a useful indication for the evaluation of nitrogen fixation in nodules of symbiotic plant.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.123-130
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• 2002

A field experiment was carried out to determine the effect of application level of animal manure on the nitrate nitrogen concentration, sugar content and animal intake of forage sorghum $\times$ sudangrass hybrid (Sorghum bicolor (L.) Moench, cv. Pionee. 988) in 1995. The application amount of animal manure were 50, 100 and 150MT in cattle manure, 20, 40 and 80MT in swine manure, and 10, 20 and 40MT/ha in poultry manure. Non-application plot(control) was involved. The nitrate nitrogen concentration was increased with increasing of application level of animal manure(P<0.05). Average nitrate nitrogen concentration was 397, 512, and 609mg/kg at low, medium and high application level of animal manure. The nitrate nitrogen concentration by plant height was 438mg/kg at 50~60m of plant height, 454mg at 100~120cm, and 418mg at 200~220cm. The nitrate nitrogen concentration of stems was 376mg, and significantly higher than that(135mg) of leaves(P<0.05) regardless of animal manure type, and lower parts of stems and leaves were significantly higher than those of upper parts of plants(P<0.05). Average nitrate nitrogen concentration of leaves was 151mg at lower, and 58mg at upper parts of plants, and the concentration of stems was 357mg at lower, 511mg at middle, and 610mg at upper parts of plants. The sugar contents of sorghum $\times$ sudangrass hybrid was decreased with increasing of application level of animal manure(P<0.05). Average sugar content was 4.9, 4.4, and 4.3。 at low, medium and high application level of animal manure. The sugar content by plant height was 3.9。 at 50~60 and 100~120cm of plant height, and 6.1。 at 200~220cm of plant height. Animal intake of sorghum $\times$ sudangrass hybrid was decreased greatly with increasing of application level of animal manure. Average intake was 73.9, 55.7, and 52.3% at low, medium and high application level of animal manure. The intake by animal manure type was 73.7% in cattle, 59.7% in swine and 62.5% in poultry manure.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1112-1117
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• 2011

This study was conducted to recommend nitrogen (N) top dressing based on soil nitrate content for leaf perilla under forcing culture in Gumsan-gun and Milyang-si. Experimental design was the randomized complete block design for five N fertilization levels and conventional fertilization. Dry weight, nitrogen uptake, and the node number of leaf perilla were measured and soil nitrate contents were analyzed monthly. The amount of nitrogen uptake for growth of a node with two leaves was $2.2kg\;10a^{-1}$ for Gumsan site and $3.5kg\;10a^{-1}$ for Milyang site. Lower level of soil nitrate N concentration for standard N fertilization was determined as $10mg\;kg^{-1}$ for both sites. Soil depth, bulk density, utilization rate of soil nitrate N, and the amount of N uptake for growth of a node with two leaves were considered for calculation of upper level of soil nitrate N concentration. The upper levels of soil nitrate N concentration for no N fertilization were determined as $30mg\;kg^{-1}$ for Gumsan site and as $40mg\;kg^{-1}$ for Milyang site. Consequently the recommendation equations for the N top dressing were Y=-0.157X+4.71 for Gumsan site and Y=-0.1667X+6.6667 for Milyang site.

• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.357-361
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• 1999

The most harmful nitrogenous compounds in fish-breeding place using are ammonia and nitrate. Excessively high total nitrogen concentration is the signal of unbalance for breeding fishes in seawater and may result overfeeding or overstocking without seawater treatment system. The failure of elimination for the organic ingredients or nitrogen compounds can also cause the consequence of inadequate oxygen concentration in seawater, either. The study shows the effect of biofilter and W disinfector of seawater in the fish- breeding place. In the results, these tools had ammonia, nitrite, nitrate and decreased 71.8%, 27.6% and 1%, respectively, and the total number of microorganisms decreased up to 81.9%.

• 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 the Korean Society of Safety
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• v.5 no.2
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• pp.40-49
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• 1990

For the determination of polluant NOx in ambient air, nitrate ion-selective electrode(ISE) was made. To comparison of NOx in each method, the nitrate-ISE, NEBA, Orion electrode were used to determinee NOx in ambient air. In this work, the concentration of NOx in ambient air was average 0.06ppm. The results were good agreement with those obtained by each method within a relative error of 3％, Absorbing efficiency of nitrogen oxides in ambient air was good for Alkali solution. The determination of nitrogen oxides in ambient air using the Aliquat 336N-PVC membrane electrode was one of the useful method. The best characteristics of the Aliquat 336N-PVC me,mbrane electrode were obtained with the ion-exchanger concentration level of 6.5-9.1 percent by weight. The optimal membrane composition, was 9.09wt.％ of ion-exchanger, 30.95wt.％ of PVC, 60.6wt.％ of plasticizer (DBP), and 0.5mm of thickness. Under the above condition, the electrode approached the Nernstian slope most closely, and the linear response ranges produced the best results.

• 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.