• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.421-427
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• 2020

In this study, we investigated the effect of nutrient supply periods on the fruit growth and quality of 'Duke' blueberry. The nutrient solution was contained with NO₃-N 4.6, NH₄-N 3.4, PO₄-P 3.3, K 3.0, Ca 4.6, and Mg 2.2 mmol·L^-1, and EC in the nutrient solution was 1.5 ds.m^-1. In 2017 and 2018, an individual blueberry bush was supplied with 8 L of the nutrient solution per week. In 2018, the drainage water quality of growing medium and fruit quality was investigated. The nutrient supply was started from April 01, and stopped at 15 days intervals as follows, 15 days before final harvest, at the final harvest date (June 30), 15 days after final harvest (DAFH), 30 DAFH, 45 DAFH, and 60 DAFH. The content of inorganic components in the growing medium was not significantly different by the stop time of nutrient supply, but the content of phosphorus (P₂O₅) tended to increase with the delay of stop time of nutrient supply. There were no significant differences in the fruit quality characteristics in terms of size, sugar content, and acidity among the different stop time of nutrient supply. The blueberry yield was tended to decrease with the delay of periods of nutrient supply, while the lowest yield of 1.8 kg was recorded when nutrient supply stopped at 45 and 60 DAFH.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.674-684
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• 2018

The purpose of this study is to construct ecological pond using LID technique in order to create naturally comfortable community space in urban idle space. The specification of the ecological pond is $110m^2$ of surface area, $0.45{\pm}0.02m$ of average depth, and bed material is composed of gravel (diameter ${\leq}60mm$), sand (diameter ${\leq}2mm$) and bentonite. Rainfall and water depth monitoring were conducted to determine the annual characteristics of inflow of the water for the ecological pond, result of total rainfall was 1,287 mm and showed a seasonal imbalance that accounted for 71.3% (918 mm) during July to August, but the annual mean water depth was kept constant at $0.45{\pm}0.02m$ due to the secondary water source. Annual trends of basic water quality showed a significant changes according to the season, such as water temperature ($5.2{\sim}28.8^{\circ}C$), DO (5.0 ~ 13.8 mg/L), EC ($113{\sim}265{\mu}S/cm$). BOD, COD, TN, and TP in physicochemical water quality tended to increase after October, but the ion parameters such as $NH_3$ and $PO_4{^{3-}}$ were generally low. Phytoplankton indicators Chl-a and BGA (blue green algae) showed a sharp increase from July to August, and green algae (Selenastrum bibraianum, Pediastrum boryanum etc.) and filamentous blue green algae (Phormidium sp.) emerged as a dominant species. The ion parameters ($F^-$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$) were strongly correlated with the $Cl^-$ as a conservative substance (R=0.70~0.97, p<0.05). Water quality was influenced by the ambient environment such as seasonal changes or rainfall, and it was closely related to fluctuation of the inflow of the water. In the future, it is necessary to consider ecological connections by referring to the characteristics surveyed in this study in order to effectively manage the water quality and biodiversity of the ecological pond in idle space.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.39-46
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• 2015

Objective of this research was to investigate the influence of compositions and concentrations of fertilizer solutions on the vegetative growth and nutrient uptake of 'Seolhyang' strawberry. To achieve this, the solutions of acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) were prepared at concentrations of 100 or $200mg{\cdot}L^{-1}$ based on N and applied during the 100 days after transplanting. The changes in chemical properties of the soil solution were analysed every two weeks, and crop growth measurements as well as tissue analyses for mineral contents were conducted 100 days after fertilization. The growth was the highest in the treatments with BF, followed by those with NF and AF. The heaviest fresh and dry weights among treatments were 151.3 and 37.8 g, respectively, with BF $200mg{\cdot}L^{-1}$. In terms of tissue nutrient contents, the highest N, P and Na contents, of 3.08, 0.54, and 0.10%, respectively, were observed in the treatment with NF $200mg{\cdot}L^{-1}$. The highest K content was 2.83%, in the treatment with AF $200mg{\cdot}L^{-1}$, while the highest Ca and Mg were 0.98 and 0.42%, respectively, in BF $100mg{\cdot}L^{-1}$. The AF treatments had higher tissue Fe, Mn, Zn, and Cu contents compared to those of NF or BF when fertilizer concentrations were controlled to equal. During the 100 days after fertilization, the highest and lowest pH in soil solution of root media among all treatments tested were 6.67 in BF $100mg{\cdot}L^{-1}$ and 4.69 in AF $200mg{\cdot}L^{-1}$, respectively. The highest and lowest ECs were $5.132dS{\cdot}m^{-1}$ in BF $200mg{\cdot}L^{-1}$ and $1.448dS{\cdot}m^{-1}$ in BF $100mg{\cdot}L^{-1}$, respectively. For the concentrations of macronutrients in the soil solution of root media, the AF $200mg{\cdot}L^{-1}$ treatment gave the highest $NH_4$ concentrations followed by NF $200mg{\cdot}L^{-1}$ and AF $100mg{\cdot}L^{-1}$. The K concentrations in all treatments rose gradually after day 42 in all treatments. When fertilizer concentrations were controlled to equal, the highest Ca and Mg concentrations were observed in AF followed by NF and BF until day 84 in fertilization. The BF treatments produced the highest $NO_3$ concentrations, followed by NF and AF. The trends in the change of $PO_4$ concentration were similar in all treatments. The $SO_4$ concentrations were higher in treatments with AF than those with NF or BF until day 70 in fertilization. These results indicate that compositions of fertilizer solution should to be modified to contain more alkali nutrients when 'Seolhyang' strawberry is cultivated through inert media and nutri-culture systems.

• 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.19 no.5
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• pp.401-418
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• 2000

1. Production of the artificial zeolite from coal ash Coal fly ash is mainly composed of several oxides including $SiO_2$ and $Al_2O_3$ derived from inorganic compounds remained after burning. As minor components, $Fe_2O_3$ and oxides of Mg, Ca, P, Ti (trace) are also contained in the ash. These components are presented as glass form resulting from fusion in the process of the combustion of coal. In other word, coal ash may refer to a kind of aluminosilicate glass that is known to easily change to zeolite-like materials by hydrothermal reaction. Lots of hot seawater is disposing near thermal power plants after cooling turbine generator periodically. Using seawater in the hydrothermal reaction caused to produce low price artificial zeolite by reduction of sodium hydroxide consumption, heating energy and water cost. As coal ash were reacted hydrothermally, peaks of quartz and mullite in the ash were weakened and disappeared, and new Na-Pl peaks were appeared strengthily. Si-O-Si bonding of the bituminous coal ash was changed to Si-O-Al (and $Fe^{3+}$) bonding by the reaction. Therefore the produced Na-Pl type zeolite had high CEC of 276.7 $cmol^+{\cdot}kg^{-1}$ and well developed molecular sieve structure with low concentration of heavy metals. 2. Utilization of the artificial zeolite in agro-environment The artificial zeolite(1g) could remove 123.5 mg of zinc, 164.7 mg copper, 184.4 mg cadmium and 350.6 mg lead in the synthetic wastewater. The removability is higher 2.8 times in zinc, 3.3 times in copper, 4.7 times in cadmium and 4.8 times in lead than natural zeolite and charcoal powder. When the heavy metals were treated at the ratio of 150 $kg{\cdot}ha^{-1}$ to the rice plant, various growth inhibition were observed; brownish discoloration and death of leaf sheath, growth inhibition in culm length, number of panicles and grains, grain ripening and rice yield. But these growth inhibition was greatly alleviated by the application of artificial zeolite, therefore, rice yield increased $1.1{\sim}3.2$ times according to the metal kind. In addition, the concentration of heavy metals in the brown rice also lowered by $27{\sim}75%$. Artificial Granular Zeolites (AGZ) was developed for the purification of wastewater. Canon exchange capacity was 126.8 $cmol^+{\cdot}kg^{-1}$. AGZ had Na-Pl peaks mainly with some minor $C_3S$ peaks in X-ray diffractogram. In addition, AGZs had various pore structure that may be adhere the suspended solid and offer microbiological niche to decompose organic pollutants. AGZ could remove ammonium, orthophosphate and heavy metals simultaneously. Mixing ratio of artificial zeolite in AGZs was related positively with removal efficiency of $NH_4\;^+$ and negatively with that of $PO_4\;^{3-}$. Root growth of rice seedling was inhibited severely in the mine wastewater because of strong acidity and high concentration of heavy metals. As AGZ(1 kg) stayed in the wastewater(100L) for 4days, water quality turned into safely for agricultural usage and rice seedlings grew normally.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.213-231
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• 2000

이 연구의 목적은 다공성의 CPP 내부에 쥐의 장골의 골수에서 유래된 세포를 접종하고 3차 원적으로 배양하여 CPP가 골 형성을 위한 조직공학의 지지체로 적용가능한가를 연구하는 것과 Calcium PolyPhosphate(CPP)의 돌연변이 유발성을 검사하는 것이다. 무수 ($Ca(H_2PO_4)$)를 condensation하여 무결정의 ($Ca(PO_3)$)를 얻고 이를 용융하고 냉각시킨 후 분쇄하여 Calcium polyphosphate(CPP) powder를 얻었다. 다공성의 CPP는 5% $SiO_2$를 첨가하여 sponge 형태로 $450-550{\mu}m$ 소공의 크기를 가지는 것과(CPP-45ppi) $200-300{\mu}m$의 소공의 크기를 가지는 것(CCP-60ppi) 2가지로 제작하였다. 각각의 CPP matrices는 $5mm{\times}5mm{\times}1mm$의 블록 형태로 만들었다. 체중 100g 내외의 백서에서 장골(femur, tibia)을 채취하여 백서의 장골 골수 세포를 분리하여 배양한 후 24well에 CPP block을 넣고 CPP block 당 $10^5$개의 배양한 세포를 접종하였다. 배양 1, 7, 14, 및 21 일째에 각 well에서 trypsin EDTA를 이용하여 2회 반복하여 cell을 분리하였고, 원심분리한 후 hemacytometer로 측정하였다. 또, 45ppi와 60ppi, 그 리 고 Tissue Culture Polystyrene(control group)에 접종, 배양된 세포들의 염기성 인산분해효소활성도를 배양 7, 14, 및 21 일째에 각각 측정하였다. 각 기간별로 배양된 세포-CPP 혼합체내에서 세포의 부착 및 증식과 형성된 조직의 3차원적 형태를 관찰하기 위하여 주사전자현미경하에서의 관찰하였다. CPP의 돌연변이 유발성 검사 (mutagenicity test)를 위해 hypoxanthine-guanine phosphoribosyl transferase(HPRT) assay를 하였다. NIH3T3 cell line과 CHO-K1 cell line으로 각각 $1000{\mu}g/m{\ell}$, $100{\mu}g/m{\ell}$, $10{\mu}g/m{\ell}$ 그리고 $1{\mu}g/m{\ell}$의 CPP 농도에서 측정하였다. 통계적 분석을 위해서 모든 측정은 각군당 4개체 이상 시험하였고, 각 측정값은 평균값${\pm}$표준편차로 나타내었다. 각 군간의 통계적 유의성 검정을 위해서 Analysis of variance(ANOVA)를 이용하였고 Tukey의 방법으로 사후분석을 실시하였다. 제작된 CPP matrices 소공들이 서로간에 연결이 잘 되어있는 형태였다. 두 가지로 제조된 CPP(45ppi와 60ppi) 모두에서 세포의 부착이 잘 일어났고, 부착된 세포의 분열도 잘 일어났다. 2 가지의 CPP 모두에서 7, 14, 21일째의 세포 수는 1일째에 비해 유의성 있게 증가하였다(P<0.01). 3차원적 구조인 Calcium PolyPhosphate에서 배양한 세포는 24well dish(tissue culture polystyrene)에서 평면적으로 배양한 대조군의 세포에서 보다 염기성 인산분해효소 (Alkaline Phosphatase)를 유의성 있게 높게 나타냈다. 주사전자현미경에서 세포-CPP 혼합체를 관찰한 결과, CPP block에 세포들이 잘부착되어 있었고, 시간이 지남에 따라 세포가 여러 층을 형성하면서 뭉치는 현상을 보였다. 또, HPRT assay 결과 , Calcium PolyPhosphate는 돌연변이 유발성을 보이지 않았다. 이상의 결과로 볼 때 CPP에는 세포부착이 잘 일어나고, 지지체 상에서 세포의 분열도 활발하게 일어나므로 골조직을 위한 조직공학의 우수한 지지체가 될 수 있을 것으로 사료된다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.83-89
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• 2004

In this work, HA/$TiO_2$ biocomposite to get high mechanical properties with biocompatibility were prepared. HA/$TiO_2$ biocomposite powders were prepared by mixing $TiO_2$ and HA powders which were synthesized through sol-gel, precipitation and hydrothermal methods. The mixing ratio was fixed at 1:1 ratio (HA/$TiO_2$, wt%). HA/$TiO_2$ biocomposite powders showed different microstructures depending on their particle size and shape. The smaller particles were coated on the surface of larger particles, whereas they were well mixed and dispersed when both $TiO_2$ and HA were nanocrystallites. HA/$TiO_2$ biocomposite powders with homogeneous microstructure showed high sintered density and good mechanical properties.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.330-336
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• 1999

In biological systems, the mineral that forms hard tissue is of an apatitic nature, and hydroxyapatite($Ca_5OH(PO_4)_3$: HA) is generally considered as the prototype for such a mineral. Thus, the precipitation of HA, having biological implications, has been the subject of several investigations. Crystal growth studies using HA seeds in supersaturated solutions have enhanced our understanding of the process and mechanism involved in seeded crystal growth. From these studies, it has become apparent that the precipitation rate of HA onto the seed crystals depends on the various conditions, especially on the additives. The relation between the supersaturated solution containing fluoride and the process of HA crystal growth enhances the understanding of mechanism of HA crystal growth. Until recently, the studies have been on the crystal growth of enamel minerals and synthetic HA seeds in the supersaturated solution containing 1~2 ppm fluoride. The purpose of the present investigation is to study the effect that fluoride of high concentration has on the crystal growth kinetics of HA. In order to produce the composition found in the secretory enamel fluid, experimental solutions of 1mM Ca, 3mM P, and 100mM Tris as background electrolyte were used. Then this experimental solutions were added to 0, 2, 4, 6, 8, 10 ppm fluoride. The effect of fluoride at high concentrations on the precipitation was examined in a bench-top crystal growth model adopting a miniaturized reaction column. Chemical analysis was employed for characterization of working solutions before and after the experimentation. Remarkable findings were : 1) the amount of crystal growth was gradually accelerated as the fluoride concentration increased until 6 ppm, but decreased in 8 and 10 ppm fluoride; 2) the amount of fluoride ion consumed in crystal formation was constant despite the increase in fluoride concentration.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.143-148
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• 2009

This study was carried out to detennine the optimal submerged culture conditions for the growth increase of ginseng adventitious roots containing germanium by means of a fractional factorial design with four factors and three levels, using the response surface methodology (RSM). The ginseng (Panax ginseng CA. Meyer) adventitious roots were induced by plant growth regulators and cultured in a liquid SH medium. The effects of various $GeO_2$ and phosphoric acid ($H_3P0_4$) concentrations in the medium, $GeO_2$ addition time and the pH of the medium on the fresh weight of the ginseng adventitious roots were investigated. The optimum pH of the medium and the phosphoric acid concentration detennined by the partial differentiation of the model equation were 4.7 and 6.0 roM, respectively. The predicted optimal $GeO_2$ concentration was 10 ppm and the $GeO_2$ addition time did not affect the growth of ginseng adventitious roots. Under these conditions, the growth of the ginseng adventitious root containing germanium was predicted to be 2.47 g.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.109-116
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• 2002

The objective of this study was to know the qualities of soil and shallow groundwater in plastic film house fields around Central Part of Korea. The study was conducted at 11 sites in Suweon, Hwasung, Pyungtaek, Yongin and Chuncheon through May to August in 1999. Soil textures of plastic films house were mainly sandy loam or loam. Electric conductivity and organic matter content of surface soils mostly exceeded the critical levels for crop production. Average concentration of $NO_3-N$ in the sha]low groundwater was 19.1 mg/L, and it reached almost the limiting level of agricultural groundwater quality (20 mg/L). Moreover about 36% of survey sites exceeded the limiting level of agricultural groundwater quality. Sulfate concentrations also at some sites exceeded agricultural groundwater quality limit level (50 mg/L). Nitrate-N, one of the most important factors in the groundwater quality, had positive correlations with other ions in foundwater.