• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.83-91
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• 2021

BACKGROUND: Cultivation area using agricultural plastic film facilities in Korea is rapidly increasing every year; however, it accelerates the salt accumulation in soils due to repeated cultivation and excessive use of chemical fertilizers. Coal ash contains various trace elements and has high potential to be used in agricultural purposes. This research was aimed to improve the quality of salts-accumulated soils and crop growth grown in the plastic film facilities using the soil amendment derived from coal ash and zero-valent iron powder. METHODS AND RESULTS: Soil amendment used in the study was manufactured using coal ash with iron powder and subjected to a typical upland soil for soil quality enhancement and two salts-accumulated soils for crop growth. After one month incubation of the salts-accumulated soils treated with the soil amendment, soil pH increased significantly and soil EC decreased by approximately 50%, compared to the control or the treatment without the soil amendment. Since the soil salts' concentration is proportional to EC, the subjected soil amendment can be proposed as an effective way to overcome soil salts accumulation in agricultural plastic film facilities. For crop growth, the length of roots and stems increased by approximately 10% and the dry weight also increased by a maximum of 75%, compared to the control. CONCLUSION: The soil amendment made from waste resources such as coal ash and zero-valent iron was found to not only be effective in improving salt-accumulated soils and crop yield but also be safe against harmful heavy metals.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.1048-1058
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• 2012

This paper proposes the DDMPF(Distributed Data Management Protocol using FAT) which prevents data loss and keeps the security of self-organized storages by comprising a client, a storage server, and a verification server in clouding environment. The DDMPF builds a self-organized storage server, solves data loss by decentralizing the partitioned data in it in contrast to the centralized problem and the data loss caused by the storage server problems of existing clouding storages, and improves the efficiency of distributed data management with FAT(File Allocation Table). And, the DDMPF improves the reliability of data by a verification server's verifying the data integrity of a storage server, and strengthens the security in double encryption with a client's private key and the system's master key using EC-DH algorithm. Additionally, the DDMPF limits the number of verification servers and detects the flooding attack by setting the TS(Time Stamp) for a verification request message and the replay attack by using the nonce value generated newly, whenever the verification is requested.

• Journal of Life Science
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• v.23 no.5
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• pp.643-649
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• 2013

In this study, we examined the antioxidative activities of ethanol extracts obtained from three plants; Lithospermum erythrorhizon Siebold & Zucc., Xanthium strumarium Linn, and Lonicera japonica, which have traditionally been used as drugs in Eastern medicine in Korea. Their extraction yields were 7.01%, 2.92%, and 7.95% in Lithospermum erythrorhizon Siebold & Zucc., Xanthium strumarium L, and Lonicera japonica, respectively. The contents of the phenolic compounds were $4.3{\pm}0.1{\mu}g/ml$, $5.4{\pm}0.1{\mu}g/ml$, and $4.6{\pm}0.1{\mu}g/ml$ in Lithospermum erythrorhizon Siebold & Zucc., and Xanthium strumarium L, respectively. Furthermore, the radical scavenging activity measured through the DPPH assay appeared highest in the Lonicera japonica's extract, and its $EC_{50}$ was 0.24 mg/ml. Compared to the control, the xanthine oxidase inhibiting activities of all extracts were effective at 0.01 mg/ml concentration. Superoxide radical scavenging activity in Lithospermum erythrorhizon Siebold & Zucc. and Lonicera japonica was more than 80%, with a concentration of 50 mg/ml. OH radical scavenging activity was 40% in the three plants, with a concentration of 50 mg/ml scavenging activity. From our results, we demonstrated that the ethanol extracts of three medicinal plants have antioxidant activities and could be potential candidates for natural antioxidants.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.347-349
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• 1998

Slow sand filtration was modified and applied for the determination of eliminating efficacy of various fungi and for recommending an easy approach to growers. After 1,500 liter filtration, Fusarium oxysporum was eliminated by several substrates such as activated charcoal (92.5% elimination), silica (90.8%), vermiculite (90.5%), sand (82.3%), perlite (50.4%), and hydroball (21.2%). Silica was able to eliminate several fungi by maximal ratio, which was corresponded to Fusarium oxysporum 120 cfu/mL. Collectotrichum lagenarium 98 cfu/mL. Phytophthora capsici 82 cfu/mL, Botrytis cinerea 62 cfu/mL, Pythium spp. 42 cfu/mL, and Sclerotinia ssp. 52 cfu/mL. In this case, the change of EC was minor and pH was maintained to about 7. In deep flow culture of 'Ddooksum Cheokchookmyeon' lettuce and 'Seokwang' tomato, silica-, activated charcoal-, and vermiculite-based filtration system successfully eliminated Fusarium oxysporum and Phytophthora capsici from the nutrient solution. As a result, these plants were not diseased by ten weeks after inoculation. With this system, growers can easily control the root-zone fungi in the recirculating hydroponic system.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.697-703
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• 2006

Endocrine disruptors were measured with GC/MS in effluents discharged from sewage treatment processes in pilot scale for the purpose of water reuse. From that analysis, we compared the removal rate of them by treatment processes. Nonylphenol was mainly detected in effluents and high concentration from 0.36 to 0.94 ${\mu}g/L$. $17{\beta}$-estradiol(E2) and $17{\alpha}$-ethynylestradiol(EE2) were detected as below the limit of detection in effluent. Endocrine disruptors were removed effectively in the range from 50 to 100% by treatment process. EC50 value($9.0{\times}10^{-3}$ M) of $17{\beta}$-estradiol(E2) by dose response curve of E-screen assay has higher than that of bisphenol A($2.736{\times}10^{-5}M$) and p-octylphenol($9.760{\times}10^{-6}$ M). These results showed that alkylphenols have lower relative estrogen potency than other estrogens such as $17{\beta}$-estradiol(E2). Calculated estrogenic activity(ng-EEQ/L) was 2 times higher than measured total estrogenic activity which estimated by E-screen assay. Moreover estrogenic activity of effluent by treatment process showed very low as below 1 ng-EEQ/L.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.353-360
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• 2003

For the simple rapid bioassay of organophosphorus and carbamate pesticide residues, a mass-production system of acetycholinesterase (AChE, EC 3.1.1.7, MAChE) using baculovirus and insect cell culture was constructed. The cDNA for AChE was synthesized from Drosophila melanogaster in Halla Mountain, the lipid anchor tail was removed by PCR and was used for the site-directed mutagenesis of three amino acid residues (E107Y, F368L, L408F). The mutated cDNA was inserted into the baculovirus vector and expressed in insect cells. Maximum cell growth and enzyme activity were reached when the cells $(2{\times}10^6\;cell/ml)$ were infected four times at four-day-intervals. His-tag containing MAChE was purified using Ni-NTA column and used for characterization. The activity was maintained under various pHs (3-10) and temperatures $(20-50^{\circ}C)$ under experimental conditions. As an extraction solution for pesticides, methanol is more effective than ethanol. Against major organophosphate and carbamate pesticides, the MAChE showed better sensitivity than AChE and AChE from housefly (Taiwan).

• Journal of Life Science
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• v.23 no.7
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• pp.869-878
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• 2013

Eleven functional plant materials were identified via a literature search, and their antioxidant capacity and inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells were tested. Yields from hot water extracts of the materials were the highest (52.10%) in Lycii fructus, and the yields from Phellinus linteus were the lowest (5.7%). The yields of another were 14.50-42.47%. Total phenol and flavonoids contents were the highest in P. linteus. The $EC_{50}$ values for DPPH and ABTS radical scavenging activities were lower than $100{\mu}g/ml$ for Salvia miltiorrhiza, whereas the values for P. linteus, Scutellaria baicalensis, and Paeonia lactiflora were $100-200{\mu}g/ml$. The $EC_{50}$ value for the superoxide anion radical scavenging activity of all the extracts was higher than $300{\mu}g/ml$. P. linteus for the reducing power was shown the highest activity. $Fe^{2+}$ chelating activity was the highest in the Morus alba extract. In an MTT assay, the cell viability of the RAW264.7 LPS-exposed cells was above 80% in extracts of $50{\mu}g/ml$ and above 77% in extracts of $100{\mu}g/ml$ in all the plant materials except Acanthopanax sessiliflorum. NO production in the RAW264.7 LPS-exposed cells showed a 12-fold increase compared to the control. The NO production level of all the extracts was $6.86-26.18{\mu}M$. Notably, $100{\mu}g/ml$ of S. baicalensis extract showed a remarkable decrease in NO production (72%) compared with the control. The potent antioxidant and anti-inflammatory activities of S.baicalensis, P. linteus, S. miltiorrhiza, M. alba, and P. lactiflora suggest that they are potential candidates as functional materials.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.277-280
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• 2005

In order to prevent chestnuts from damage by the peach pyralid moth, Dichocrosis punctiferalis, a sprinkler system was installed on the chestnut orchard. Such a test was conducted at Yeoju-gun, Gyeonggi-do, Korea in 2002. Insecticides of fenitrothion 50% EC, x1,000 and diflubenzuron 25% Wp, x2,500 were sprayed at ten-day fifteen-day and twenty-day intervals during the period of D. punctiferalis adult occurrence by sprinkler system. The peach pyralid moths generally emerged for about 60 days from early July to early September, and peak emergence was 10 days from late July to early August. Damage rate of chestnuts were 0.9-4.0% on average with this crown insecticide spraying with diflubenzuron, while 30.4% when not treated. Control effectiveness of this insecticide spraying was 92%(86.7-97.0%). In conclusion, effectual times and number of insecticide application with sprinkle system against peach pyralid moth were from early July to late August and four or five times at ten or fifteen day intervals, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.4
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• pp.345-350
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• 1997

Characteristics of electrical conductivity(EC) of seventy one-greenhouse soil located in southern part of Korea were surveyed to obtain the basic information for sustainable management of plastic film house soils. The averaged soil EC were 5.84 and 2.49dS/m for top-and sub-soil, respectively, showing distribution of 11.3% for top-soils and 50.7% for sub-soils within the optimum level of 2.0 dS/m. On the whole, the soils with flowering plants revealed higher EC than those with fruiting vegetables showing 2.75~6.34dS/m for the former and 2.29(sub-soils)~5.13dS/m(top-soils) for the latter. In a view of soil sampling time, the soils at Feb., 1996 marked 4.3~37.7% and 10.3(top-soils)~11.3%(sub-soils) higher EC compared with the soils at Sept. and Dec., 1995, respectively. The linear regression correlation coefficients of soil minerals to EC were in oder of $Mg^{2+}$ > $NO_3{^-}$ > $Cl^-$ > $Ca^{2+}$ > $SO_4{^{2-}}$ > $K^+$ for top-soils and were $Cl^-$ > $SO_4{^{2-}}$ > $NO_3{^-}$ > $Ca^{2+}$ > $Mg^{2+}$ > $K^+$ for sub-soils. In especial, the concentration of soil EC accompanied the increasing population ratio of soil fungi to bacteria and/or actinomycetes.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.103-113
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• 2012

본 연구에서는 하수재이용에 따른 논에서의 토양염분 변화를 추정하기 위하여 경기도 화성시 수원환경사업소 인근에 위치한 병점지구를 대상으로 수문순환과 작물성장과의 관계를 고려한 SWAP (Soil-Water-Atmosphere-Plant) 모형을 이용하여 평가하였다. 실험에 사용한 관개용수는 지하수 (TR#1), 하수처리장 방류수+여과+UV (TR#3)로 분류하여 모형에 사용하였다. 유입관개수의 EC (Electrical Conductivity)는 지하수 관개수인 TR#1이 다른 처리구에 비해 작았고, TR#3의 경우 0.442~0.698 dS $m^{-1}$의 범위를 보였다. 모형의 보정과 검정을 위해서 대상지구에 FDR (Frequency Domain Reflection)을 설치하여 토양수분함유량과 염분농도를 토심에 따라 일단위로 모니터링 하였다. 토심 (50, 100, 140 cm)에 따른 토양함수량의 RMSE는 검정기간 중 TR#1에서 0.003~0.064 $cm^3\;cm^{-3}$, TR#3에서 0.001 $cm^3\;cm^{-3}$ 범위를 보여 주었고, 토양염분의 보정기간 중 토심별 RMSE는 TR#1에서 0.018~0.037 dS $m^{-1}$, TR#3에서 0.004~0.014 dS $m^{-1}$ 범위를 보여 적용성이 있는 것으로 나타났다. 토양내의 염분수지 분석 결과, 토양에서의 염분저장량이 (-)로 나타나 토양내로 침출되는 것으로 나타났으며, WMRI (Water Management Response Indicators)을 이용한 분석 결과, 높은 침투능으로 인하여 토양에서의 염분 집적 영향은 낮은 것으로 평가되었다.