• Proceedings of the Membrane Society of Korea Conference
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• 2001.05a
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• pp.135-138
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• 2001

Acrylic wastewater flux was discussed using modules of ultrafiltration hollow fiber and reverse osmosis spiral wound. The optimum backflushing times of membranes were decided and the degree of fouling was discussed with operating time. Permeate flux was decreased rapidly at 12hrs. Separation processes with ultrafiltration and reverse osmosis membranes were not suitable to remove COD and TDS. The improvement of pretreatment processes was needed.

• Korean Membrane Journal
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• v.1 no.1
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• pp.43-49
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• 1999

Separation of soluble oil was investigated during filtration of cutting oil emulsion using various commercial ultrafiltration membranes. The surface properties of membranes used were hydrophilic hydrophobic and modified surfaces by various surfactant pretreatments. Conditions varied include stirring speed transmeembrane pressure membrane type and surfactant type for pretreatment. The results give some indication of mechanisms occurring at the membrane surface. Surfactant pretreatments significantly improved water flux and UF flux of hydrophilic regenerated cellulose(up to 2.4x for YM100) and hydrophobic polysulfone (up to 2.2x for PTHK) membranes depending on surfactant type and operating conditions. The UF flux enhancement was attributed to membrane swelling and reduction of interfacial surface tension between oil droplets and membrane surface. unexpectedly the hydrophilic membranes revealed greater flux enhancement than the hydrophobic membranes. The results also showed a greater improvement in UF flux at lower operating pressure.

• Industrial Engineering and Management Systems
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• v.15 no.4
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• pp.318-323
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• 2016

In the current study, factors affecting cheese brands products in grocery stores were evaluated with an emphasis on diversity. The sample data were collected from Noushad and Pegah Milk Industry in 2015 and data were extracted, reviewed, and analyzed from 435 grocery stores in Mashhad using seemingly unrelated regression model and particle swarm optimization algorithm. Results showed that optimum amount of Kalleh product diversity is higher than other competitors in the market, and Kalleh UF diversity is 100 to 250 grams, and Kalleh UF diversity with weight of 300 to 500 grams is more than other modes of diversity, and Kalleh brand must remove tin cheese from the market. Sabah Brand also should eliminate its glass and creamy diversity from market, UF diversity is mostly welcomed in market.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.53-56
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• 2010

In this study, three kinds of cellulose fibers to crack reduction performance were evaluated and the results are as follows. Plastic shrinkage cracking is evaluated by the relative crack area, at all levels between $0.9kg/m^3$ and $1.2kg/m^3$, except for UF0.9% of upto50% showed are duction compared with Plain. In according to recommended amount of fiber in each area of the crack HF0.9>CEL1.2>UF0.6 effect of the order was more effective. While the impact strength of UF and CEL fibers until the final destruction are about five times the number of falls, HF fiber count drop was 10-18 time.

• Membrane and Water Treatment
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• v.2 no.4
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• pp.225-237
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• 2011

In this study, response of reversibility of membrane flux during chemically enhanced backwash (CEB) to changes in filtration time, filtration flux and coagulant concentration dosing during ultrafiltration (UF) process was investigated using a regression model. The model was developed via empirical modelling approach using response surface methodology. In developing the model, statistically designed UF experiments were conducted and the results compared with the model output. The results showed that the performance of CEB, evaluated in terms of the reversibility of the membrane flux, depends strongly on the changes in coagulant concentration dosage and the filtration flux. Also the response of the reversibility of membrane flux during CEB is independent of the filtration time. The variance ratio, VR << $F_{value}$ and $R^2$ = 0.98 obtained from the cross-validation experiments indicate perfect agreement of the model output with experimental results and also testify to the validity and suitability of the model to predict reversibility of the membrane flux during CEB in UF operation.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.166-168
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• 1998

막분리공정에서 분리막 오염은 투과율 감소에 큰 영향을 받는데 그 이유는 주로 막재질의 변질 및 막 표면에서의 농도 분극 현상에 기인하고 분리막의 종류 및 분획분자량의 차이에 따라 막분리 능력이 달라질 수 있다. 본 연구에서는 상용화되어 있는 UF/MF 중공사막에 미치는 막오염 정도와 세정 특성을 알아보았다. 막오염 정도는 막의 Pore size, 소재, 막구조에 따라서 단백질 수용액을 처리하여 막의 오염이 어떻게 일어나는지를 알아보았고 막오염 정도를 검토하기 위하여 초기순수에 대한 흡착후 투과량을 DOF(Degree of fouling)로 정의하였다. 막의 세정특성은 0.1N-NaOH을 사용하여 화학적 세정효과를 확인하였고 초기 순수에 대한 세정후 회복정도를 DOC(Degree of Cleaning)로 정의하였다. 또한 UF막에서 분획분자량별 특성과 MF막에서 소재별/구조적 특성이 DOF와 DOC에 미치는 영향에 대해서 알아보았다.

• Korean Membrane Journal
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• v.11 no.1
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• pp.15-20
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• 2009

The periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in tubular ceramic ultrafiltration (UF) system for Gongji stream water treatment in Chuncheon city. The filtration time (FT), which was the water-back-flushing period, 2 min with periodic 15 sec water-back-flushing showed the highest value of dimensionless permeate flux ($J/J_o$), and the lowest value of resistance of membrane fouling ($R_f$), and we acquired the highest total permeate volume ($V_T$) of 6.35 L. Consequently FT 2 min at back-flushing time (BT) 15 sec could be the optimal condition in advanced UF water treatment of Gongji stream. Then the average rejection rates of pollutants by our tubular ceramic UF system were 99.4% for Turbidity, 31.8% for $COD_{Mn}$, 22.6% for $NH_3$-N and 65.9% for T-P.

• Asian Journal of Turfgrass Science
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• v.4 no.2
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• pp.85-100
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• 1990

Turfgrass management had not been recognized as the subject to research until the social demand for turfgrass increased. This study was carried out to compare the effects of several complete fertilizers and ureaform(UF) with those of traditional fertilizers used for general agriculture. Complete fertilizers used in this study include Jandibiryo, Chojikwanri, Wonyebokbi and 18 - 18 - 18. Three exteriments were conducted in the established zoysiagrass field (over 5 years), in the recently established zoysiagrass field(1 years), and in the pots using artificially mixed media. In the established zoysiagrass, UF, Wonyebokbi, Chojikwanri and 18 - 18 - 18 resulted in higher growth rate, while Chojikkwanri and Jandibiryo showed better performance in the recently established zoysiagrass. Jandibiryo resulted in higher growth rate of zoysiagrass with the artificially mixed soil which is relatively infertile. Righer growth rates were maintained longer with UF, Jandidiryo, Chojikwanri than urea 18-18-18 and Wonyebokbi. Wonyebokbi had the characteristics of producing more stolons and rhyzomes than the other fertilizers.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.343-344
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• 2018

KAERI has about 185 tons of $D-UF_6$ from 1986 and it being stored 16 48Y type cylinders inside of storage building. The $D-UF_6$ cylinders should be transported to other countries for the deconversion into stable materials such as $U_3O_8$ in order to enhance the storage safety and disposal. For the transportation to other country and loading the cylinders to the deconversion facility, the sampling process is essential. The design and procedure for the sampling are now developing, and environmental effect evaluation and risk evaluation works will be performed to acquire license for the sampling.

• Development and Reproduction
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• v.13 no.4
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• pp.239-247
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• 2009

Hatching rate, larval deformation and growth rate of selected olive flounder (Paralichthys olivaceus) for rapid growth were compared to those of the unselected fish. Fish were spawned on the same day and cultured under the similar conditions. The selected fish had a significantly higher eggs hatching rate, and lower larval deformation. The selected fish grew significantly faster, and at the end of the experiment (8 weeks after hatching) averaged 50.49${\pm}$2.67 mm in total length, 16.30${\pm}$0.08 mm in body height, and 1.036${\pm}$0.118 g in weight, compared to 40.55${\pm}$3.13 mm, 13.50${\pm}$0.96 mm, and 0.557${\pm}$0.073 g for unselected fish, respectively. The selected fish had a significantly higher body shape index, however lower condition factor than the unselected fish. The results of the present study demonstrate that the selected fish of the olive flounder for rapid growth had superior growth and improved body shape.