• Journal of Environmental Science International
• /
• v.7 no.6
• /
• pp.833-843
• /
• 1998

It is noted that the red tides and the oxygen-deficient water mass are extensively developed in Masan Bay during summer. The nutrients mass balance was calculated in Masan Bay, using the three-dimensional numerical hydrodynamic model and the material cycle model. The material cycle model was calibrated with the data obtained on the field of the study area in June 1993. The nutrients mass balance calculated by the combination of the residual currents and material cycle model results showed nutrients of surface and middle levels to be transported from the inner part to the outer part of Masan Bay, and nutrients of bottom level to be transported from outer part to inner part of Masan Bay. The uptake rate of DIN in the box A1(surface level of inner part) was found to be 337. 5mg/$m^3$ㆍday, the largest value in all 9 boxes and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1, and the regeneration rate of DIN was found to be 78.2mg/$m^3$ㆍday in the box A3(bottom level of inner part), and that of DIP was found to be 18.6mg/$m^3$ㆍday in box A1. The regenerations of DIN and DIP in the water column of the entire Bay were found to be 7.66ton/day and 760kg/day, respectively. And the releases of DIN and DIP from the sediments of the entire Bay were found to be 2.86ton/day and 634kg/day, respectively. The regeneration rate was 2.5 times as high as the release rate in DIN, and 1.2 times in DIP. The results of mass balance calculation showed not only the nutrients released from the sediments but the nutrients regenerated in water column to be important in the control and management of water quality in Masan Bay.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.394-398
• /
• 2001

The study was carried out to investigate the water balance and losses of nutrients from paddy fields during cropping period. The size of paddy fields was 95 ha and the fields were irrigated from a pumping station. The runoff loading was the highest in June because of the high concentrations of nutrients due to applied fertilizer. When the runoff losses of nutrients were compared to applied chemical fertilizer, it was found that 39.1 % to 42.5 % of nitrogen lost via runoff while runoff losses of phosphorus account for 6.3 % to 8.0 % of the total applied amount during cropping period. When the ratio was calculated between nutrients losses by infiltration and the applied of chemical fertilizer, two year results showed 9.1 % to 10.7 % for nitrogen and 0.2 % for phosphorus, respectively.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2003.10a
• /
• pp.591-594
• /
• 2003

A field monitoring study was carried out to investigate the water balance and losses of nutrients from paddy fields in Sumjin river basin. The size of paddy fields was 115 ha and the fields were irrigated from a pumping station. The runoff loading was the highest in June because of the high concentrations of nutrients due to applied fertilizer. The surface runoff losses of T-N and T-P in runoff water were 53.4 to 68.3kg/ha(average 59.7kg/ha) and 0.38 to 2.20kg/ha(average 1.42kg/ha), respectively. When the runoff losses of nutrients were compared to applied chemical fertilizer, it was found that 42% to 60% of nitrogen lost via runoff while runoff losses of phosphorus account for 3.0% to 17.2% of the total applied amount during entire year.

• Journal of Korean Society of Rural Planning
• /
• v.8 no.1 s.15
• /
• pp.15-25
• /
• 2002

The study was carried out to investigate the water balance and losses of nutrients from paddy fields during cropping period. The size of paddy fields was 95 ha and the fields were irrigated from a pumping station. The runoff loading was the highest in June because of the high concentrations of nutrients due to applied fertilizer, When the runoff Bosses of nutrients were compared to applied chemical fertilizer, it was found that 39.1 % to 42.5 % of nitrogen lost via runoff while runoff losses of phosphorus account for 14.5 % to 17 % of the total applied amount during cropping period. When the ratio was calculated between nutrients losses by infiltration and the applied of chemical fertilizer, two year results showed 9.1% to 10.8% for nitrogen and 0.5% for phosphorus, respectively.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.445-450
• /
• 2001

The objective of this study is to develop the GLEAMS-PADDY model for nutrients loading simulation from paddy-field areas. This model is developed by modifying the GLEAMS model. The model is composed of hydrology, sediment and chemical parts. The model was evaluatd using field data. The model estimates water balance and nutrients concentrations reasonably well. The model can be applied to find BMP's in the paddy areas.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.5
• /
• pp.545-552
• /
• 2018

In this study, we performed a mesocosm experiment to estimate the mass balance of Nutrients (DIN, DIP) in a phragmites australis community. We developed 4 mesocosm tanks which is available to circulate seawater with adjustable tide levels and flooding times. Each of the mesocosm tanks were filled with phragmites australis and sediment from Jinudo in Nakdong Estuary. We investigated DIN, DIP concentrations in three layers (seawater-phragmites australis-sediment) to estimate the mass balance of Nutrients and biomass. Growth rates were also investigated. The results can be summarized as follows. 1) In spring, rhizome biomass was higher than that of aerial stem by about 6.3~9.7%. In summer, aerial stem biomass was higher than that of rhizome about 19.2~21.2 %. 2) Th Growth rate of phragmites in Mesocosm Tank A was faster than in Mesocosm Tank D by about 2 to 3 times for aerial stem and rhizome. 3) The Concentration of nutrients (DIN, DIP) in each mesocosm Tank showed 2~3 % variance in spring and summer. 4) The biomass in each mesocosm varied by about 23 % which was higher than the concentration variance for each mesocosm tanks.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.44 no.5
• /
• pp.106-115
• /
• 2002

The objective of this study was to evaluate the GLEAMS-PADDY model by applying it to estimate nutrients loading from paddy-field areas. Field data from Soro region of Chungbuk province during May to September 1999 were used for model application. Field data collected include the amounts of rainfall, irrigation water, drainage water, ET, and Percolation in hydrology Part. T-N and T-P concentrations in the rain water, irrigation water, ponded water, drainage water and percolated water were measured. The comparisons of observed and simulated water balance components and nutrient concentrations showed reasonably good agreements and the GLEAMS-PADDY model may be used to simulate nutrients loading from paddy fields. Futher research was suggested to include the erosion submodel in the GLEAMS-PADDY model to better simulate the nutrient behavior. In addition, the pesticide submodel also recommended to be included in order to simulate the various pesticide applied in paddy fields.

• Journal of the Korean Chemical Society
• /
• v.13 no.2
• /
• pp.187-193
• /
• 1969

As part of an extensive program on the microbiological oxidation of hydrocarbons, reaction conditions and nutrients consumption of candida lipolytica grown on alkane as carbon source were studied. For optimum growth of yeast, the conditions of pH 5, temperature $30^{\circ}C$, carbon number $C_{16}$& $C_{18}$aeration 25.6 1/l/hr, agitation 3000 r.p.m., hydrocarbon concentration 10% were obtained. Carbon and nitrogen balance related to these conditions were also investigated. In the course of this investigation, some significant effects of pH and carbon number of hydrocarbon variation were observed.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.21 no.4
• /
• pp.234-247
• /
• 2018

The goal of nutrition of the preterm infant is to "provide nutrients to approximate the rate of growth and composition of weight gain for a normal fetus of the same postmenstrual age and to maintain normal concentrations of blood and tissue nutrients" (American Academy of Pediatrics 2014). Failure to provide the necessary amounts of all of the essential nutrients to preterm infants has produced not only growth failure, but also increased morbidity and less than optimal neurodevelopment. This continues to be true despite many efforts to increase nutrition of the preterm infants. In contrast, enhanced nutrition of very preterm infants, both intravenous and enteral, beginning right after birth, promotes positive energy and protein balance and improves longer term neurodevelopmental outcomes. The benefits are long lasting too, particularly for prevention of later life chronic diseases.

• Journal of Environmental Science International
• /
• v.20 no.7
• /
• pp.919-927
• /
• 2011

A ecosystem model was applied for understanding of circulation process of state variables in marine ecosystem. A mass balance was conducted by calculating the physical process. The sensitivity analysis was conducted to know which coefficient is the most effective factor to the state variables in the model. The results of the mass balance indicate that the primary production was 58.6 ton C/day in the case of mass flux. DIN and DIP in nutrient ingestion of phytoplankton were each 7.9 ton N/day, 1.1 ton P/day. POC and DOC in mineralization of organic matter were each 10.8 ton C/day, 40.6 ton C/day. The results of sensitivity analysis showed that the maximum growth rate of phytoplankton was the most important factor for overall state variables. In the case of nutrients, Half saturation constant of DIN, and mineralization rate of DOM for COD were important factor.