• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.3
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• pp.146-156
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• 2002

The objective of this study was to develop a modified CREAMS model for paddy field conditions. The model simulates daily balance of water and nutrient from irrigated paddies using meteorological, irrigation, and agricultural management data. The model simulates daily evapotranspiration of paddy using Penman equation and determines daily flooding depth changes. Total nitrogen and phosphorus concentrations within flooding water, surface runoff, and leaching water from a paddy field also can be simulated. Parameters of the model were calibrated using observed data of the Agricultural Experiment Station of the Seoul National University in Suwon Korea. The model was applied for the irrigation period of paddy field in Gicheon area when 1,234 mm annual rainfall was occurred. The simulated losses of the total nitrogen and total phosphorous were 11.27 kg/ha and 0.98 kg/ha, respectively. There was a good agreement between observed and simulated data. It was found that CREAMS-PADDY model was capable of predicting runoff and nutrient losses from irrigated paddy fields.

• Environmental Engineering Research
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• v.21 no.1
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• pp.52-57
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• 2016

Sediment is a useful natural source but deteriorated continually by anthropogenic and industrial sources. Therefore, it is imperative to search a suitable method for improving or restoring sediment quality. Sediment has been tested to identify the effects of some external agents on a polluted area for 28 days. Chemical analysis and total viable counts (TVC) test have been conducted for 4 days interval to assess their performance. The analyses of chemical oxygen demand (COD), acid volatile sulfide (AVS), total phosphorous (T-P), total nitrogen (T-N) indicate that the chemical agents was more efficient to improve sediment quality whereas the microbial agent was more efficient for nutrient releasing from sediment. Oxygen releasing property of the chemical agent was thought to be providing with more congenial environment for the higher growth of the bacterial community than the direct application of microbial agents.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.188-196
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• 2014

This study aimed to understand the nutrient absorption, usage and allocation of Carpinus cordata in different soil and light environments. Seasonal changes of foliar nitrogen, phosphorous, chlorophyll contents, leaf mass per area (LMA) and nutrient retranslocation rates were investigated for C. cordata saplings growing in a natural deciduous broadleaved forest and an Manchurian fir (Abies holophylla) plantation in Gwangneung, Kyunggido. The deciduous forest had lower leaf area, higher light penetration, and better soil fertility than the Manchurian fir forest. However, available soil phosphorous content in the deciduous forest was only one third of that in the Manchurian fir forest, which caused lower foliar phosphorous content and higher P retranslocation rate of C. cordata in the deciduous forest than that in the Mancurian fir forest. Soil nitrogen contents in the deciduous forest were higher than that in the Manchurian fir forest, however, no differences in foliar nitrogen content and retranslocation rate in C. cordata between the two stands were found. C. cordata in the Manchurian fir forest with high LAI throughout a year, had lower LMA, foliar nitrogen content and chlorophyll a/b, while had higher total chlorophyll content and chlorophyll/N than that in the deciduous forest. These results implied C. cordata under different environments are using different strategies for nutrient use and allocations.

• Environmental Engineering Research
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• v.10 no.5
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• pp.247-256
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• 2005

A combination of the submerged membrane activated-sludge bioreactor(SMABR) equipped with non-woven fabric filter and oyster-zeolite (OZ) packed-bed adsorption column was studied to evaluate the advanced tertiary treatment of nitrogen and phosphorous. The non-woven filter module was submerged in the MBR and aeration was operated intermittently for an optimal wastewater treatment performance. Artificial wastewater with $COD_{Cr}$ of 220 mg/L, total nitrogen (T-N) of 45 mg/L, and total phosphorous (T-P) of 6 mg/L was used in this study. MLSS was maintained about $4,000\;{\sim}\;5,000\;mg/L$ throughout the experiments. The experiments were performed for 100-day with periodic non-woven filter washing. The results showed that $COD_{Cr}$ could be effectively removed in SMABR alone with over 94% removal efficiency. However, T-N and T-P removal efficiency was slightly lower than expected with SMABR alone. The permeate from SMABR was then passed through the OZ column for tertiary nutrients removal. The final effluent analysis confirmed that nutrients could be additionally removed resulting in over 87% and 46% removal efficiencies for T-N and T-P, respectively. The results of this study suggest that the waste oyster-shell can be effectively reclaimed as an adsorbent in advanced tertiary wastewater treatment processes in combination with SMABR equipped with non-woven fabric filter.

• Journal of Nutrition and Health
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• v.44 no.5
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• pp.394-405
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• 2011

Osteoporosis is a rising problem, as the older age population is increasing due to prolongation of life. Genetic and environmental factors play key roles in bone metabolism, and diet is also an important factor. We investigated the relationship among factors affecting bone mineral density (BMD), including daily food intake and nutrient intake in men aged >50 years. Seventy-eight men, who visited the health promotion center at one of the university medical centers, were divided into normal and osteopenia groups according to their BMD. The body weight of the normal group was significantly higher than that of the osteopenia group. The osteopenia group showed significantly higher carbohydrate intake and lower calcium and vegetable calcium intake compared to those in the normal group. Lumbar spine BMD was negatively correlated with energy, fat, vitamin B1, and sodium intake in the normal group. Additionally, femoral neck BMD was negatively correlated with total animal protein, energy, protein, fat, phosphorous, iron, animal iron, potassium, vitamin B1, B2, B6, and niacin intake. Lumbar spine BMD was positively correlated with fruit, calcium, vegetable calcium, animal calcium, and vitamin C intake in the osteopenia group. Femoral neck BMD was negatively correlated with meat, dairy product, total animal protein, plant protein, animal protein, vitamin A, and cholesterol intake. A stepwise multiple regression analysis revealed that several dietary factors affected BMD, including energy, fat, vitamin B1, B2, B6, niacin, sodium, protein, iron, animal iron, phosphorous, potassium, and animal protein in the normal group and zinc, calcium, vegetable calcium, animal calcium, vitamin C, fruit, protein, animal protein, meat, dairy product, carbohydrates, cholesterol, vegetables, mushrooms, and seasonings in the osteopenia group. These results indicate that adequate nutrient intake plays an important role maintaining optimum bone health in middle aged men.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.4
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• pp.527-532
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• 2019

Objective: Phosphorous (P) sources with greater bioavailability might increase animal production efficiency and decrease environmental pollution. The objective of current study was to determine animal performance, nutrient digestibility, blood metabolites and fecal P concentration in finishing lambs fed a diet with either di-calcium phosphate (DCP) or di-ammonium phosphate (DAP) as a P source. Methods: Twelve 4-month-old male lambs (initial body weight $24.87{\pm}3.4kg$) were randomly allocated to a diet with either DCP or DAP (~261 g/kg of total diet P) fed ad libitum for 93 days. Diets were iso-nitrogenous and iso-energetic and had same calcium (Ca) and P concentrations. Results: The DAP contained 19.7 g/kg of dry matter (DM) Ca, 185.4 g/kg DM P and 14,623 ppm fluorine, while DCP contained 230.3 g/kg DM Ca, 195.2 g/kg DM P and 1,039 ppm fluorine. The diet with DAP contained 60 ppm fluorine while the diet with DCP contained 13 ppm fluorine. Lambs fed the diet with DAP tended to have a greater daily DM intake compared to those fed diet with DCP (p = 0.09). Lambs fed DAP had greater plasma P concentration and alkaline phosphatase activity ($p{\leq}0.01$) compared with lambs fed DCP. Dry matter and organic matter digestibility of the diets were similar between two treatments at days 60 and 90, while they were greater in lambs fed DCP (p<0.05) at day 30 of the trial. Feeding DAP increased P digestibility (58.7% vs 50.2%; p<0.05) and decreased fecal P concentration in lambs compared with feeding DCP (3.1 vs 3.8 g/kg DM; p<0.05). Conclusion: Providing ~261 g/kg of total diet P as DAP in the diet of finishing lambs improved the bioavailability of P in the body and decreased excretion of P in feces without affecting lamb performance.

• Journal of the Mineralogical Society of Korea
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• v.21 no.2
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• pp.117-127
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• 2008

The characteristics of phosphate adsorption-desorption on kaolinite was studied by batch adsorption experiments and detailed adsorbed state of phosphate on kaolinite surface was investigated using ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) spectroscopy. The phosphorous contents were measured using UV-VIS-IR spectrophotometer with 820 nm wavelength. The adsorbed P was generally increased with increasing pH value in the range of pH 4 to pH 9, however it is not distinct. Moreover the adsorbed P was significantly changed with different initial phosphate concentration. The adsorption isotherms were well fitted with the Langmuir equation, Temkin equation, and Freundlich equation in descending order. The maximum Langmuir adsorption capacity of kaolinite KGa-2 is 232.5 ($204.1{\sim}256.5$) mg/kg and has very higher value than that of kaolinite KGa-1b. Most of adsorbed phosphate on kaolinite were not easily desorbed to aqueous solution, but might fixed on kaolinite surface. However it needs further research about the exact desorption experiment. It was impossible to recognize phosphorous adsorption bands on kaolinite in ATR-FTIR spectrum from kaolinite bands themselves, because the absorption peaks of phosphorous have very similar positions with those of kaolinite, and the intensities of the former were very weak in comparison with those of the latter.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.86-98
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• 2009

This study was carried out to investigate vegetation structure and soil properties of Adenophora racemosa population distributed in Jeombongsan, Seoraksan, Odaesan and Dutasan in Gangwon-do, Korea. From August 2007 until September 2009, $2m{\times}2m$ quadrate was established in native area of Adenophora racemosa in order to record a dominants and coverage, and soil factors at 22 sites. It was found that the altitude in the distributed areas for Angelica gigas population was 800 m or more. Adenophora racemosa population was classified into Rhododendron mucronulatum dominant population, Geranium var. hirsutum dominant population, Caret siderosticta dominant population and Aruncus dioicus var. kamtschaticus dominant population. In the site of study, soil pH, electrical conductivity, soil organic matter, available phosphorous, and exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable sodium concentration and total nitrogen were ranged from 5.0~7.1, 0.06~0.65dS/m, 0.96~8.94%, 12.3~32.8mg/kg, 0.12~0.89cmol+/kg, 0.34~10.08cmol+/kg, 0.1~l.4cmol+/kg, 0.02~0.29cmol+/kg and 0~8.4% respectively. According to the results of DCCA, Adenophora racemosa population were distributed in the high available phosphorous and exchangeable potassium, and Rhododendron mucronulatum dominant population was situated on low available potassium and high slope degree, Geranium var. hirsutum dominant population was high altitude, electrical conductivity and exchange magnesium, and Carex siderosticta dominant population and Aruncus dioicus var. kamtschaticus were distributed on high total nitrogen, organic matter, available phosphorous.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.611-614
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• 2003

A Korean Type Biofilter system combined with a conventional anoxic tank(septic tank) process was investigated in regard to its feasibility for removing organic as well as nutrients from the rural wastewater in Korea. At recirculation, the removal rate in BOD and SS increased slightly as much as 93 and 95% compared with non-recirculation system. On the other hand, removal rates of the total nitrogen(T-N) and total phosphorous(T-P) in recirculation system increased significantly as much as 62 and 57%, respectively compared with non-recirculation system. The recirculation system provides sufficient treatment to improve the removal rate in T-N and T-P.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.163-173
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• 2001

This study describes the characteristics of concentrations of pollutants such as total nitrogen(T-N), total phosphorous(T-P), and chemical oxygen demand(COD) at paddy areas during 2-year irrigation periods. The most common order in average concentrations of T-P and COD is podded water > irrigation(or drainage) water > percolated water. Most of pollutants concentrations in drainage water are lower than those in irrigation water after early July due to large uptake of pollutants by rice crop and denitrification. The exponential L (load)-Q(discharge) equations for classified irrigation periods are significant at 0.001 level for irrigation and drainage waters. For drainage water, the concentrations of T-N and COD slightly decrease with discharge, while the T-P concentrations slightly increase with discharge.