• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.128-134
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• 2013

In the summer season (June~August) during the study period of Lake Doam, average concentrations of major water quality parameters, COD, SS, TN, and TP were 4.0, 16.2, 3.129 and $0.077mg\;L^{-1}$, respectively, and Chl-a was $11.8mg\;m^{-3}$. The result has indicated that Lake Doam was a meso-eutrotrophic lake. Lake Doam data from the summer season (June~August), precipitation from 2001 to 2012, and water quality (COD, SS, TN, TP, Chl-a etc.) of seven years (2001, 2002, 2004 and 2009~2012), were statistically analyzed for long-term trends by Mann-Kendall test and Sen's slope estimator methods. The statistical results showed that precipitation, SD, COD, TN, $NO_3-N$, $NH_3-N$ and Chl-a had decreasing trends, and EC, turbidity, SS, TP and DIP had increasing trends. Suspended solids and total phosphorus were directly affected by precipitation. In the case of suspended solids, more aggressive and constructive plans need to be implemented than the current turbidity reduction project to achieve the targeted water quality ($5mg\;L^{-1}$ of SS) in Lake Doam. In particular, we need to specify a project that considers the steep topographic characteristics of high, land farming areas and precipitation conditions of the Lake Doam watershed, which can increase the efficiency of a turbidity reduction project.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.2
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• pp.82-91
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• 2002

The study was executed to evaluate the agricultural utilization of phyllite as composting bulking agent in pig manure. The effects of the composted pig manure were verified by adopting the mixture of 10% phyllite and 20% saw dust(PSPC 10) and 20% phyllite and 10% saw dust(PSPC 20). The pig manure mixed with 30% saw dust was used as a control(PSC). However C/N ratio was very decreased because humus was rapidly progressed at PSPC 20 plot during the composting. Also, $NH_4{^+}-N$, $NO_3{^-}-N$, pH and EC were quickly changed from after one week and CEC was the highest as $92cmol_c/kg$. And Total-N was hardly changed during the composting but total carbon was rapidly declined as processing compost. Therefore, the phyllite has positively showed comparing with others in the street as compost bulking agent and go ahead, it is concerned that this material should have to research and investigating, constantly.

• Molecules and Cells
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• v.23 no.3
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• pp.280-286
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• 2007

L-asparaginase (EC 3.5.1.1) catalyzes the hydrolysis of the amide group of L-asparagine, releasing aspartate and $NH_4{^+}$. We isolated a low temperature-inducible cDNA sequence encoding L-asparaginase from soybean leaves. The full-length L-asparaginase cDNA, designated GmASP1, contains an open reading frame of 1,258 bp coding for a protein of 326 amino acids. Genomic DNA blotting and fluorescence in situ hybridization showed that the soybean genome has two copies of GmASP1. GmASP1 mRNA was induced by low temperature, ABA and NaCl, but not by heat shock or drought stress. E. coli cells expressing recombinant GmASP1 had 3-fold increased L-asparaginase activity. A possible function of L-asparaginase in the early response to low temperature stress is discussed.

• Macromolecular Research
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• v.16 no.3
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• pp.204-211
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• 2008

A platinum-catalyzed polyelectrolyte porous membrane was prepared by solid-state compression of electrospun polystyrene (PS) fibers and in-situ metallization of counter-balanced ionic metal sources on the polymer surface. Using this ion-exchange metal-polymer composite system, fiber entangled pores were formed in the interstitial space of the fibers, which were surrounded by sulfonic acid sites ($SO_3^-$) to give a cation-selective polyelectrolyte porous bed with an ion exchange capacity ($I_{EC}$) of 3.0 meq/g and an ionic conductivity of 0.09 S/cm. The Pt loading was estimated to be 16.32 wt% from the $SO_3^-$ ions on the surface of the sulfonated PS fibers, which interact with the cationic platinum complex, $Pt(NH_3)_4^{2+}$, at a ratio of 3:1 based on steric hindrance and the arrangement of interacting ions. This is in good agreement with the Pt loading of 15.82 wt% measured by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The Pt-loaded sulfonated PS media showed an ionic conductivity of 0.32 S/cm. The in-situ metallized platinum provided a nano-sized and strongly-bound catalyst in robust porous media, which highlights its potential use in various electrochemical and catalytic systems.

• Journal of Climate Change Research
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• v.6 no.4
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• pp.311-318
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• 2015

Emission characteristics from charbroiling of four different meats (beef, port, duck and chicken) in a pilot-scale cooking facility were investigated in this study. The analyzed air pollutants include gaseous species (CO, NO, $SO_2$, $NH_3$ and PAHs) as well as particulate matters (TSP, $PM_{10}$, $PM_{2.5}$ and black carbon). The emission factors of $PM_{10}$ and PAHs were in the range of 3~47 g-PM/kg-meat and 0.6~11.41 mg-PAHs/kg-meat, respectively, depending on the type of a meat. In addition, the results also revealed that the high ratio of $PM_{2.5}$ to TSP in a meat charbroiling should be considered to design and to operate air pollution control devices.

• Journal of Environmental Science International
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• v.32 no.4
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• pp.205-220
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• 2023

In this study, impact of the COVID-19 outbreak on PM_2.5 mass and its five chemical components (NH₄⁺, NO₃^-, SO₄^2-, OC, EC) in Busan was evaluated, and compared with that of Seoul. The study period over the recent three years was sub-divided into two periods: Pre-COVID (2018~2019) and COVID (2020) periods, and the differences in observed annual and monthly variations between the two periods were explored here. The results indicated that annual mean PM_2.5 mass concentrations decreased during the COVID period by 16% in Seoul and 29% in Busan, and the satellite-observed annual average of aerosol optical depth (AOD) over the Korean Peninsula also decreased by approximately more than 10% compared with that of the Pre-COVID period. All of the five chemical components decreased but no particular changes were found in their fractions occupied during the COVID period. However, over the Lock-down period (2020-March), the sulfate fraction decreased in Seoul, mostly reflecting the recent Chinese trends of aerosol characteristics, whereas the nitrate fraction considerably decreased in Busan, which was attributable to the local emission changes and their variabilities in Busan. Other meteorological characteristics such as higher frequencies of easterly winds in the Busan area during the COVID period were also discussed in comparison with those in the Seoul area.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.193-201
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• 2013

This research was conducted to investigate the influence of compositions and concentrations of fertilizer solution on growth of lettuce as well as changes in chemical properties of root media. To achieve this three kinds of fertilizers such as acidic (AF), neutral (NF), and alkaline fertilizer (BF) were formulated and applied with the concentrations of 100 or $200mg{\cdot}L^{-1}$ based on nitrogen concentrations. The growth characteristics were investigated 10 weeks after transplant and the analysis of soil solution for chemical characteristics were conducted in every week. The BF was more effective than AF in crop growth of blue leaf lettuce 10 weeks after transplant and the treatment of BF200 showed the heaviest fresh and dry weights among all treatments tested. The treatment of BF also showed the highest growth followed by those of NF and AF in growth of red leaf lettuce, but the growth in treatments of $100mg{\cdot}L^{-1}$ were higher than those of $200mg{\cdot}L^{-1}$ in the three kinds of fertilizers. The differences among treatments in soil solution pH became larger from week 6. The pH in the treatment of $200mg{\cdot}L^{-1}$ was lower than that of $100mg{\cdot}L^{-1}$ when AF was applied, but the treatment of $200mg{\cdot}L^{-1}$ showed higher pH than that of $100mg{\cdot}L^{-1}$ in case of BF. The electrical conductivity of soil solution in treatments of $200mg{\cdot}L^{-1}$ were 0.2 to 0.4 unit higher than those of $100mg{\cdot}L^{-1}$ when those are measured as $dS{\cdot}m^{-1}$ in three kinds of fertilizers. The $NH_4$ concentrations were higher in the treatments of AF than those of BF, but the concentrations of Ca, Mg and $NO_3$ were vice verse. The concentrations of $PO_4^{-3}$ were the highest in the treatments of AF followed by those of NF and BF when three kinds of fertilizers were applied with equal nitrogen concentrations. The differences of nutrient concentrations in soil solution of root media were influenced by composition of fertigation solution and varied soil solution pH.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.268-273
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• 1998

Changes of chemical component and losses of chemical fertilizer by infiltration water from 0.5ha of paddy field in Chinan area of Chonbuk province during the rice cultivation were investigated. The infiltration water samples were collected in a ceramic porous cup which was a buried at the 30, 50, 70, 90㎝ of soil depth. pH of infiltration water ranged $6.64{\sim}7.90$ and EC showed $324{\sim}647{\mu}$S/cm. The content of total-N, $NH_4-N$ and $NO_3-N$ were $0.58{\sim}14.59$, $0.05{\sim}4.25$, and $0.15{\sim}7.71mg/L$ respectively. The content of total-P and ortho-P were $0.009{\sim}0.077mg/L$ and $0{\sim}0.029mg/L$ The content of $Ca^{++}$, $Mg^{++}$, $Na^{+}$ and $K^{+}$ showed $0.88{\sim}4.78$, $0.22{\sim}1.04$, $0.17{\sim}0.98$, and $0.84{\sim}3.19㎎/L$. These all at the first transplanting are higher than that of other periods. The content of $SO_4^{2-}$ showed $3.92{\sim}18.72mg/L$ and decreased with a soil depth. However $Cl^-$ of infiltration water ranged $9.03{\sim}19.97mg/L$ and no difference with a soil depth. When infiltrated $2,416.5m^{3}$ of an infiltration water from 0.5ha of paddy field during the rice cultivation, losses of chemical components were 20.34㎏/㏊ of total-N, 3.54㎏/㏊ of $NH_4-N$, 10.44㎏/㏊ of $NO_3-N$, 0.16㎏/㏊ of total-P and 0.028㎏/㏊ of ortho-P. Also $Ca^{++}$, $Mg^{++}$, $Na^+$, $K^+$, $SO_4^{2-}$ and $Cl^-$ were lost 10.24, 2.84, 2.84, 7.22, 50.04 and 62.20㎏/㏊ respectively. There were lost by infiltration water 9.35% of nitrogen, 0.59% of phosphorous and 22.79% of potassium in applied chemical fertilizer.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.291-295
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• 1998

Changes of chemical components and natural supplies by precipitation at agricultural zone in Chinan area of Chonbuk province from May 1, 1997 to April 30, 1998 were investigated. pH of precipitation ranged $6.44{\sim}7.24$ and EC showed $14.23{\sim}30.67{\mu}S/cm$. The $total{\sim}N$, NH4-N and NO3-N were $1.43{\sim}10.14$, $0.57{\sim}4.39$, and $0.18{\sim}1.69㎎/L$ respectively. The content of total-P showed $0.015{\sim}0.087㎎/L$ but ortho-P was not detected. The content of suspended solid, $Ca^{++}$, $Mg^{++}$, $Na^+$ and $K^+$ showed $3.6{\sim}15.3$, $0.37{\sim}1.66$, $0.17{\sim}0.52$, $0.22{\sim}0.87$, and $0.17{\sim}0.58㎎/L$. The content of SO42- and Cl- showed $3.37{\sim}014.47㎎/L$ and $1.02{\sim}7.24㎎/L$ respectively. Only Cu and Zn of heavy metals were detected $0{\sim}0.019㎎/L$ and $0.009{\sim}0.098㎎/L$ but Cd, Cu, Ni and Cr were not detected. Natural supplies of chemical components were 39.48㎏/ha/yr of total-N, 21.82㎏/ha/yr of $NH_4-N$, 6.90㎏/ha/yr of $NO_3-N$ and 0.68㎏/ha/yr of total-P. Also $Ca^{++}$, $Mg^{++}$, $Na^+$, $K^+$, $SO_4^{2-}$ and $Cl^-$ were supplied 14.46, 5.00, 7.26, 5.46, 98.76 and 31.16㎏/ha/yr respectively. Only of heavy metals were supplied 0.024㎏/ha/yr of Cu and 0.044㎏/㏊/yr of Zn.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.484-492
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• 2014

We quantified the effects of the composition and concentration of fertilizer solutions on the growth and nutrient uptake of 'Maehyang' strawberry at the vegetative growth stage. Acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) with concentrations of 100 or $200mg{\cdot}L^{-1}$ based on N, were formulated and applied during the 100 days after transplanting, at which point crop growth and tissue nutrient contents were analyzed. The soil solutions were sampled every two weeks to measure the pH, EC and nutrient concentrations. BF was a more effective fertilizer compared to AF and NF for growth of 'Maehyang' strawberry when fertilizer concentrations were controlled to $100mg{\cdot}L^{-1}$. By contrast, the fresh and dry weights were greatest in the NF treatment when fertilizer concentrations were controlled to $200mg{\cdot}L^{-1}$. The tissue contents of N, P, and Na were 2.20, 0.51 and 0.10%, respectively, in the NF 200 treatment, and these were the highest among all treatments tested. The highest contents of K, Ca and Mg were 2.60% in AF 200, 0.95% in BF 200 and 0.45% in BF 100, respectively. During the fertilization period, the highest and lowest pHs were 6.13 in BF 100 and 4.92 in AF 200. The lowest EC was $1.376dS{\cdot}m^{-1}$ in BF 100 and the highest was $4.936dS{\cdot}m^{-1}$ in NF 200 treatments. The highest $NH_4{^+}$ concentrations in the soil solution occurred during the AF 200 treatment, followed by those with NF 200 and AF 100. When fertilizer concentrations were equal, AF treatment gave rise to the highest $Ca^{+2}$ and $Mg^{+2}$ concentrations, followed by NF and BF, until day 84 of fertilization. The BF treatments had the highest $NO_3{^-}$ concentrations followed by NF and AF. The trends for $PO_4^{-3}$ concentrations were similar in all fertilizer treatments when the fertilizer concentrations were equal. The above results indicate that neutral and basic fertilizers were most effective to promote 'Maehyang' strawberry growth when fertilizer solutions were controlled to low or high concentrations, respectively. These findings are useful for planning fertilization programs for vegetative propagation of 'Maehyang' strawberry.